Portable Wideband Directional Antenna Scheme with Semicircular Corrugated Reflector for Digital Television Reception

This research proposed a portable wideband horizontally-polarized directional antenna scheme with a radome for digital terrestrial television reception. The operating frequency band of the proposed antenna scheme is 470–890 MHz. The portable antenna scheme was an adaptation of the Yagi-Uda antenna, consisting of a folded bowtie radiator, a semicircular corrugated reflector, and a V-shaped director. Simulations were carried out, and an antenna prototype was fabricated. To validate, experiments were undertaken to assess the antenna performance, including the impedance bandwidth (|S11| ≤ −10 dB), gain, and unidirectionality. The measured impedance bandwidth was 75.93%, covering 424–943 MHz, with a measured antenna gain of 2.69–4.84 dBi. The radiation pattern was of unidirectionality for the entire operating frequency band. The measured xz- and yz-plane half-power beamwidths were 150°, 159°, 160° and 102°, 78°, 102° at 470, 680, and 890 MHz, with the corresponding cross-polarization below −20 dB and −40 dB. The radome had a negligible impact on the impedance bandwidth, gain, and radiation pattern. The power obtained for the outdoor test, at 514 MHz, was 38.4 dBµV (−70.4 dBm) with a carrier-to-noise ratio (C/N) of 11.6 dB. In addition, the power obtained for the indoor test was 26.6 dBµV (−82.2 dBm) with a C/N of 10.9 dB. The novelty of this research lies in the concurrent use of the Yagi-Uda and bowtie antenna technologies to improve the impedance bandwidth and directionality of the antenna for digital terrestrial television reception.


Introduction
In recent years, attempts have been made to synthesize diverse antenna technologies to improve the impedance bandwidth of antennas for digital television reception. Specifically, in [1], a wideband dipole antenna for digital television reception was proposed using a multi-loop radiator and a coplanar waveguide feed. In [2], an antenna with seven resonance pads on the ground plane was proposed to improve the impedance bandwidth.
As a result, further attempts were made to develop antennas for digital television reception with wide impedance bandwidth, high gain, and stable radiation pattern throughout  Figure 1 shows the geometry of the portable wideband directional antenna scheme for digital terrestrial television reception, and Figure 2 illustrates the proposed antenna scheme of 75 Ω input impedance with radome. The proposed antenna scheme was an adaptation of the Yagi-Uda antenna, consisting of the folded bowtie radiator, semicircular corrugated reflector, and V-shaped director.

Antenna Structure
concerned with the fabrication of the prototype antenna and experimental results. Section 5 discusses the indoor and outdoor application testing. The concluding remarks are provided in Section 6. Figure 1 shows the geometry of the portable wideband directional antenna scheme for digital terrestrial television reception, and Figure 2 illustrates the proposed antenna scheme of 75 Ω input impedance with radome. The proposed antenna scheme was an adaptation of the Yagi-Uda antenna, consisting of the folded bowtie radiator, semicircular corrugated reflector, and V-shaped director. concerned with the fabrication of the prototype antenna and experimental results. Section 5 discusses the indoor and outdoor application testing. The concluding remarks are provided in Section 6. Figure 1 shows the geometry of the portable wideband directional antenna scheme for digital terrestrial television reception, and Figure 2 illustrates the proposed antenna scheme of 75 Ω input impedance with radome. The proposed antenna scheme was an adaptation of the Yagi-Uda antenna, consisting of the folded bowtie radiator, semicircular corrugated reflector, and V-shaped director. The folded bowtie radiator and the corrugated reflector were made of a thin stainlesssteel sheet (0.2 mm in thickness). The semicircular reflector was corrugated to reduce the overall physical size of the antenna while increasing its electrical size. In addition, the V-shaped director was made of a hollow aluminum tube 8 mm in diameter. The director was incorporated to improve the directivity and gain of the antenna.

Antenna Structure
The three elements (i.e., the folded bowtie radiator, corrugated reflector, and V-shaped director) were mounted on a circular plastic supporting plate 165 mm in diameter. The antenna was fed by a coaxial cable connected to a 75 Ω F-type connector, and a balun (λ/4 coaxial balun) was utilized to convert unbalanced to balanced output signal. The portable wideband directional antenna was also covered with a 0.5 mm-thick cylindrical acrylonitrile butadiene styrene (ABS) radome 175 and 209 mm in diameter and height.
Simulations were carried out to optimize the antenna parameters using CST Microwave Studio Suite [31]. Table 1 tabulates the optimal physical dimensions of the portable wideband directional antenna scheme for the 470-890 MHz frequency band. (Note: The experimental results revealed that the ABS radome had a negligible effect on the antenna performance, including the impedance bandwidth, gain, and radiation pattern).

Conceptualization of the Portable Directional Antenna Scheme
Figure 3a-c illustrates the conceptualization of the proposed portable wideband directional antenna scheme for digital terrestrial television reception, starting with the Yagi-Uda antenna (model I), the modified antenna with the U-shaped reflector and director (model II), and the proposed antenna scheme (model III).
Model I is the Yagi-Uda antenna of a wire-type structure. The main advantages of the Yagi-Uda antenna are unidirectionality and high gain. However, model I suffered from a narrow impedance bandwidth. Given the center frequency of 680 MHz, the length of the radiator element was λ C /2 (220.58 mm), where λ C was the wavelength of the center frequency.  Model I is the Yagi-Uda antenna of a wire-type structure. The main advantages of the Yagi-Uda antenna are unidirectionality and high gain. However, model I suffered from a narrow impedance bandwidth. Given the center frequency of 680 MHz, the length of the radiator element was λC/2 (220.58 mm), where λC was the wavelength of the center frequency.
In model II, to improve the impedance bandwidth, the radiator element of model I was replaced with the folded bowtie radiator. The wire reflector was replaced with the stainless-steel U-shaped reflector, and the director was reshaped into the U shape. In model III, the U-shaped reflector was corrugated to reduce the overall physical size of the antenna while increasing the electrical size. Moreover, the corrugated reflector improved the electromagnetic reflection of the proposed antenna scheme [32,33]. The U-shaped director was reshaped into the V shape for the antenna compactness without compromising the antenna performance. Figure 4 compares the simulated impedance bandwidth (|S11| ≤ −10 dB) of the antenna models I, II, and III. Model I achieved a narrow impedance bandwidth, covering 620-700 MHz. The narrow impedance bandwidth rendered model I operationally unsuitable for digital television reception. Model II experienced an impedance mismatch between 590-780 MHz, rendering it operationally inapplicable. Model III achieved the simulated impedance bandwidth of 63.85%, covering 468-907 MHz, which encompassed the target frequency band (470-890 MHz). Figure 5 compares the antenna gain of models I, II, and III.  In model II, to improve the impedance bandwidth, the radiator element of model I was replaced with the folded bowtie radiator. The wire reflector was replaced with the stainless-steel U-shaped reflector, and the director was reshaped into the U shape. In model III, the U-shaped reflector was corrugated to reduce the overall physical size of the antenna while increasing the electrical size. Moreover, the corrugated reflector improved the electromagnetic reflection of the proposed antenna scheme [32,33]. The U-shaped director was reshaped into the V shape for the antenna compactness without compromising the antenna performance. Figure 4 compares the simulated impedance bandwidth (|S 11 | ≤ −10 dB) of the antenna models I, II, and III. Model I achieved a narrow impedance bandwidth, covering 620-700 MHz. The narrow impedance bandwidth rendered model I operationally unsuitable for digital television reception. Model II experienced an impedance mismatch between 590-780 MHz, rendering it operationally inapplicable. Model III achieved the simulated impedance bandwidth of 63.85%, covering 468-907 MHz, which encompassed the target frequency band (470-890 MHz). Figure 5 compares the antenna gain of models I, II, and III. Model I is the Yagi-Uda antenna of a wire-type structure. The main advanta the Yagi-Uda antenna are unidirectionality and high gain. However, model I su from a narrow impedance bandwidth. Given the center frequency of 680 MHz, the l of the radiator element was λC/2 (220.58 mm), where λC was the wavelength of the c frequency.
In model II, to improve the impedance bandwidth, the radiator element of m was replaced with the folded bowtie radiator. The wire reflector was replaced wi stainless-steel U-shaped reflector, and the director was reshaped into the U shape. In m III, the U-shaped reflector was corrugated to reduce the overall physical size of the an while increasing the electrical size. Moreover, the corrugated reflector improve electromagnetic reflection of the proposed antenna scheme [32,33]. The U-shaped directo reshaped into the V shape for the antenna compactness without compromising the an performance. Figure 4 compares the simulated impedance bandwidth (|S11| ≤ −10 dB) o antenna models I, II, and III. Model I achieved a narrow impedance bandwidth, cov 620-700 MHz. The narrow impedance bandwidth rendered model I operatio unsuitable for digital television reception. Model II experienced an impedance mis between 590-780 MHz, rendering it operationally inapplicable. Model III achieve simulated impedance bandwidth of 63.85%, covering 468-907 MHz, which encompass target frequency band (470-890 MHz). Figure 5 compares the antenna gain of models I, III.

Evolution of the Portable Wideband Antenna Scheme
This section discusses the evolutionary stages of the proposed portable wide directional antenna scheme (model III), consisting of three antenna generations: second, and third generations. As shown in Figure 7, the first generation was the an scheme without a reflector and director, and the second generation was the an scheme with the corrugated reflector but without the director. The third generation the proposed portable wideband directional antenna scheme with the corrugated ref

Evolution of the Portable Wideband Antenna Scheme
This section discusses the evolutionary stages of the proposed portable wideban directional antenna scheme (model III), consisting of three antenna generations: firs second, and third generations. As shown in Figure 7, the first generation was the antenn scheme without a reflector and director, and the second generation was the antenn scheme with the corrugated reflector but without the director. The third generation wa the proposed portable wideband directional antenna scheme with the corrugated reflecto and the V-shaped director.

Evolution of the Portable Wideband Antenna Scheme
This section discusses the evolutionary stages of the proposed portable wideband directional antenna scheme (model III), consisting of three antenna generations: first, second, and third generations. As shown in Figure 7, the first generation was the antenna scheme without a reflector and director, and the second generation was the antenna scheme with the corrugated reflector but without the director. The third generation was the proposed portable wideband directional antenna scheme with the corrugated reflector and the V-shaped director.  Figure 8 compares the simulated impedance bandwidth (|S11| ≤ −10 dB) of the first-, second-, and third-generation antenna schemes. The first-generation antenna scheme achieved a narrow impedance bandwidth, covering 830-925 MHz, rendering the scheme operationally unsuitable for digital terrestrial television reception. The impedance bandwidth of the second-generation antenna scheme closely resembled that of the third-generation scheme, covering a 468-907 MHz frequency band. Both the second-and third-generation antenna schemes covered the entire target operating frequency band of 470-890 MHz. However, the overall gain of the third-generation antenna scheme was higher than that of the second-generation scheme, as shown in Figure 9.    However, the overall gain of the third-generation antenna scheme was higher than that of the second-generation scheme, as shown in Figure 9.  The first-generation antenna scheme achieved a n impedance bandwidth, covering 830-925 MHz, rendering the scheme operationally unsuita digital terrestrial television reception. The impedance bandwidth of the second-generation a scheme closely resembled that of the third-generation scheme, covering a 468-907 MHz freq band. Both the second-and third-generation antenna schemes covered the entire target op frequency band of 470-890 MHz. However, the overall gain of the third-generation antenna s was higher than that of the second-generation scheme, as shown in Figure 9.    Figure 10 compares the simulated xz-and yz-plane radiation patterns of the first-, second-, and third-generation antenna schemes. The radiation pattern of the first-generation antenna scheme was of omnidirectionality due to the absence of the corrugated reflector ( Figure 7a). The first-generation scheme failed to cover the entire target operating frequency band ( Figure 8). The radiation patterns of the second-and third-generation antenna schemes were closely similar. However, the gain of the third-generation scheme was higher than that of the second-generation scheme.  Sensors 2022, 22, 5338 Figure 10 compares the simulated xz-and yz-plane radiation patterns of th second-, and third-generation antenna schemes. The radiation pattern of t generation antenna scheme was of omnidirectionality due to the absence of the cor reflector ( Figure 7a). The first-generation scheme failed to cover the entire target o frequency band (Figure 8). The radiation patterns of the second-and third-ge antenna schemes were closely similar. However, the gain of the third-generation was higher than that of the second-generation scheme.

Surface Current Distribution
This section focuses on the third-generation antenna scheme (i.e., the p portable wideband directional antenna scheme) due to its wide impedance ban (Figure 8), high gain (Figure 9), and unidirectional radiation pattern ( Figure 10).

Surface Current Distribution
This section focuses on the third-generation antenna scheme (i.e., the proposed portable wideband directional antenna scheme) due to its wide impedance bandwidth (Figure 8), high gain (Figure 9), and unidirectional radiation pattern ( Figure 10). Figure 11a-c illustrates the simulated surface current distribution of the proposed portable wideband directional antenna scheme at 470, 680, and 890 MHz, respectively. At 470 MHz (the first resonant frequency), the currents are concentrated around the feeding point and along the corrugated reflector, as shown in Figure 11a. In Figure 11b, at 680 MHz (the second resonant frequency), the currents are concentrated around the feeding point, the lower part of the balun, and the upper edge of the corrugated reflector. At 890 MHz (the third resonant frequency), the currents are concentrated around the feeding point, the folded bowtie radiator, and the balun, as shown in Figure 11c. Essentially, the thirdgeneration antenna scheme (i.e., the proposed portable wideband directional antenna scheme) covered the target frequency band for the digital terrestrial television reception of 470-890 MHz, as indicated in Figure 8. point and along the corrugated reflector, as shown in Figure 11a. In Figure 11b, at 680 MHz (the second resonant frequency), the currents are concentrated around the feeding point, the lower part of the balun, and the upper edge of the corrugated reflector. At 890 MHz (the third resonant frequency), the currents are concentrated around the feeding point, the folded bowtie radiator, and the balun, as shown in Figure 11c. Essentially, the third-generation antenna scheme (i.e., the proposed portable wideband directional antenna scheme) covered the target frequency band for the digital terrestrial television reception of 470-890 MHz, as indicated in Figure 8.

Parametric Sweep of the Antenna Scheme
This section investigates the effect of variable antenna parameters on the impedance bandwidth of the proposed portable wideband directional antenna scheme. The results are graphically presented in Figures 12-15.  Figure 12a,b shows the simulated impedance bandwidth (|S 11 | ≤ −10 dB) under various widths of the folded bowtie radiator (W di ; 20, 25, 30, 35, and 40 mm) and angles of the folded bowtie radiator (AG dp ; 0, 7.5, 15, 22.5, and 30 • ). As shown in Figure 12a,b, the optimal W di and AG dp were 30 mm and 15 • , respectively.
In addition, the optimal length of the triangular section of the folded bowtie radiator (D dp ) was 18.7 mm, and the optimal height of the folded bowtie radiator (h mi ) was 15 mm. The optimal width of the first and second sections of the folded bowtie radiator (W mi ) were 15.2 and 15.2 mm, while the optimal width of the final section of the folded bowtie radiator (W r ) was 6.9 mm. The optimal length of one arm of the folded bowtie radiator was thus 101 mm. In other words, the optimal overall length of the folded bowtie radiator was 202 mm. Figure 13a,b shows the simulated impedance bandwidth (|S 11 | ≤ −10 dB) under variable distance from the center of the supporting plate to the reflector (D ref ) and reflector length (L ref ). As shown in Figure 13a Figure 12a,b, the optimal Wdi and AGdp were 30 mm and 15°, respectively.
In addition, the optimal length of the triangular section of the folded bowtie radiator (Ddp) was 18.7 mm, and the optimal height of the folded bowtie radiator (hmi) was 15 mm. The optimal width of the first and second sections of the folded bowtie radiator (Wmi) were 15.2 and 15.2 mm, while the optimal width of the final section of the folded bowtie radiator (Wr) was 6.9 mm. The optimal length of one arm of the folded bowtie radiator was thus 101 mm. In other words, the optimal overall length of the folded bowtie radiator was 202 mm.   Figure 15a,b shows the simulated impedance bandwidth (|S 11 | ≤ −10 dB) under variable balun height (H balun ) and distance from the center to the center of the balun (D balun ). The optimal H balun and D balun were 140.32 mm and 19.24 mm, respectively. Meanwhile, the antenna height (h di ; 156 mm) and the spacing between the lower base plate and the reflector (h; 139 mm) were proportional to the balun height (H balun ) ( Table 1). Figure 16a,b depicts the prototype of the portable wideband directional antenna scheme for digital terrestrial television reception without and with ABS radome. Experiments with the antenna prototype (75 Ω input impedance) were carried out in an anechoic chamber using a 50 Ω vector network analyzer (Agilent E5061B) [34]. The impedance transformer (TME ZT-205) was used to match a 75 Ω antenna with a 50 Ω measurement system.  Figure 13a,b shows the simulated impedance bandwidth (|S11| ≤ −10 dB) under variable distance from the center of the supporting plate to the reflector (Dref) and reflector length (Lref). As shown in Figure 13a,b, the optimal Dref and Lref were 78.61 mm and 226.42 mm, respectively, covering the target operating frequency band of 470-890 MHz. Figure  13c shows the simulated impedance bandwidth under variable reflector height (href) (25,45,65, and 85 mm), and Figure 13d illustrates the corresponding simulated radiation pattern at 890 MHz. The larger href improved the back lobe level (i.e., front-to-back ratio), especially in the upper frequency band. In Figure 13d, despite the high back lobe level of −21.3 dB under href = 85 mm, the final antenna was bulky. As a result, the reflector height (href) of 45 mm, with a back lobe level of −14.14 dB, was selected for compactness. Figure 14a-c shows the simulated impedance bandwidth (|S11| ≤ −10 dB) under variable distance between the director and the center of the supporting plate (Ddi), the director's arm length (Ldi), and the angle of the director's arm (AGdi). The optimal Ddi, Ldi, and AGdi were 25 mm, 43.34 mm, and 34.6 mm, respectively, covering the target operating frequency band of 470-890 MHz. Figure 15a,b shows the simulated impedance bandwidth (|S11| ≤ −10 dB) under variable balun height (Hbalun) and distance from the center to the center of the balun (Dbalun). The optimal Hbalun and Dbalun were 140.32 mm and 19.24 mm, respectively. Meanwhile, the antenna height (hdi; 156 mm) and the spacing between the lower base plate and the reflector (h; 139 mm) were proportional to the balun height (Hbalun) ( Table 1). Figure 16a,b depicts the prototype of the portable wideband directional antenna scheme for digital terrestrial television reception without and with ABS radome. Experiments with the antenna prototype (75 Ω input impedance) were carried out in an anechoic chamber using a 50 Ω vector network analyzer (Agilent E5061B) [34]. The impedance transformer (TME ZT-205) was used to match a 75 Ω antenna with a 50 Ω measurement system.     As shown in Figure 19, the radiation pattern of the proposed portable wid horizontally polarized directional antenna scheme was of unidirectionality. The mea xz-and yz-plane cross-polarizations were below −20 dB and −40 dB, respectively, wi corresponding HPBW of 150°, 159°, and 160° and 102°, 78°, and 102° at 470 MHz, 680 and 890 MHz, respectively. The discrepancy between the simulated and measured polarization could be attributed to the use of self-trapping screws in the antenna prot fabrication, as shown in Figure 16a. The measured xz-and yz-plane back lobe levels below −9 dB. The experiments also revealed that the ABS radome had negligible im on the impedance bandwidth and the antenna gain, vis-à-vis the antenna scheme w the ABS radome. Table 2 tabulates the simulated and measured performance proposed portable wideband directional antenna scheme. Table 3 shows a comp between previous works and the proposed portable wideband directional an scheme.  As shown in Figure 19, the radiation pattern of the proposed portable wide horizontally polarized directional antenna scheme was of unidirectionality. The meas xz-and yz-plane cross-polarizations were below −20 dB and −40 dB, respectively, wit corresponding HPBW of 150°, 159°, and 160° and 102°, 78°, and 102° at 470 MHz, 680 M and 890 MHz, respectively. The discrepancy between the simulated and measured c polarization could be attributed to the use of self-trapping screws in the antenna proto fabrication, as shown in Figure 16a. The measured xz-and yz-plane back lobe levels below −9 dB. The experiments also revealed that the ABS radome had negligible im on the impedance bandwidth and the antenna gain, vis-à-vis the antenna scheme wi the ABS radome. Table 2 tabulates the simulated and measured performance o proposed portable wideband directional antenna scheme. Table 3 shows a compa between previous works and the proposed portable wideband directional ant scheme. As shown in Figure 19, the radiation pattern of the proposed portable wideband horizontally polarized directional antenna scheme was of unidirectionality. The measured xz-and yz-plane cross-polarizations were below −20 dB and −40 dB, respectively, with the corresponding HPBW of 150 • , 159 • , and 160 • and 102 • , 78 • , and 102 • at 470 MHz, 680 MHz, and 890 MHz, respectively. The discrepancy between the simulated and measured crosspolarization could be attributed to the use of self-trapping screws in the antenna prototype fabrication, as shown in Figure 16a. The measured xz-and yz-plane back lobe levels were below −9 dB. The experiments also revealed that the ABS radome had negligible impacts on the impedance bandwidth and the antenna gain, vis-à-vis the antenna scheme without the ABS radome. Table 2 tabulates the simulated and measured performance of the proposed portable wideband directional antenna scheme. Table 3 shows a comparison between previous works and the proposed portable wideband directional antenna scheme.    [20] Printed dipole antenna 452-897 (65.97%) 2.09-3.85 45 × 250 × 1.6 (0.070λ × 0.391λ × 0.002λ) [21] Printed dipole antenna 441-890 (67.46%) 4.65 (peak) 35 × 243 × 1.6 (0.054λ × 0.380λ × 0.002λ) [23] Printed loop antenna 461-806 (54.45%) 1.9-2.5 165 × 165 × 0.8 (0.258λ × 0.258λ × 0.001λ) [24] Printed quasi-Yagi antenna 450-848 (61.32%) 3.5-4.6 200 × 240 × 1.6 (0.313λ × 0.376λ× 0.002λ) [26] Log

Indoor and Outdoor Application Testing
The proposed portable wideband directional antenna scheme was tested for the indoor and outdoor reception of digital terrestrial television signals in the 470-862 MHz frequency range. This research was conducted in Thailand, which adopted the DVB-T2 standard for digital terrestrial television broadcasting. As a result, the indoor and outdoor tests were carried out within the 470-862 MHz frequency band.
The transmitting station is located in Thailand's capital Bangkok at the coordinates 13 • 45 16 N 100 • 32 24 E, with an effective isotropic radiated power (EIRP) of 50 kW. The broadcast range encompasses the capital and neighboring provinces in the central region, as indicated by the area in pink in Figure 20. The height of the transmission antenna was 328.4 m. The receiving antenna (i.e., antenna under test (AUT)) for both the indoor and outdoor testing was located at the coordinates 14 • 20 52 N 100 • 33 55 E, which is 65.73 km from the transmitting station. In the indoor and outdoor testing, the AUT was placed at a height of at least 10 m above ground. The transmitting and receiving (AUT) antennas were in the line of sight.  Figure 21 shows the experimental setup for the outdoor and indoor testing of the proposed portable wideband directional antenna scheme with a digital video broadcasting (DVB) signal receiver (Promax Ranger Neo + ). The measurements were taken in a concrete building. Figure 22 depicts the outdoor reception performance of the proposed antenna scheme at the first multiplexer (MUX) of 514 MHz in Thailand for the DVB-T2 system [35]. The power obtained was 38.4 dBµV (−70.4 dBm), with a carrier to noise ratio (C/N) of 11.6 dB. The signal spectrum was of a Rician fading channel, rendering the proposed antenna scheme suitable for outdoor digital terrestrial television reception [34].  Figure 21 shows the experimental setup for the outdoor and indoor testing of the proposed portable wideband directional antenna scheme with a digital video broadcasting (DVB) signal receiver (Promax Ranger Neo + ). The measurements were taken in a concrete building. Figure 22 depicts the outdoor reception performance of the proposed antenna scheme at the first multiplexer (MUX) of 514 MHz in Thailand for the DVB-T2 system [35]. The power obtained was 38.4 dBµV (−70.4 dBm), with a carrier to noise ratio (C/N) of 11.6 dB. The signal spectrum was of a Rician fading channel, rendering the proposed antenna scheme suitable for outdoor digital terrestrial television reception [34].     Figure 24 shows the experimental setup used to assess the reception performance of the proposed antenna scheme in actual use, whereby the AUT was connected by a 75 Ω RG6 coaxial cable to the set top box and a television set. The results indicate that the     Figure 24 shows the experimental setup used to assess the reception performance of the proposed antenna scheme in actual use, whereby the AUT was connected by a 75 Ω RG6 coaxial cable to the set top box and a television set. The results indicate that the      Figure 24 shows the experimental setup used to assess the reception performance of the proposed antenna scheme in actual use, whereby the AUT was connected by a 75 Ω RG6 coaxial cable to the set top box and a television set. The results indicate that the  Figure 24 shows the experimental setup used to assess the reception performance of the proposed antenna scheme in actual use, whereby the AUT was connected by a 75 Ω RG6 coaxial cable to the set top box and a television set. The results indicate that the proposed antenna scheme is capable of receiving the transmitted signals from all television channels, as evidenced by high-quality images and sound. proposed antenna scheme is capable of receiving the transmitted signals from all television channels, as evidenced by high-quality images and sound. Figure 24. The experimental setup for the reception test in actual use.

Conclusions
This research proposed a portable wideband of a horizontally polarized directional antenna scheme with a radome for digital terrestrial television reception (470-890 MHz). The proposed antenna scheme was adapted from the Yagi-Uda antenna, consisting of a folded bowtie radiator, semicircular corrugated reflector, and V-shaped director. The radome was of thin cylindrical ABS material. Simulations were carried out to optimize the antenna parameters. An antenna prototype was fabricated, and experiments were undertaken to determine the antenna performance. The performance metrics included the impedance bandwidth (|S11| ≤ −10dB), gain, and unidirectionality. The results indicated that the folded bowtie radiator enhanced the impedance bandwidth of the antenna. The corrugated reflector improved the impedance bandwidth and unidirectionality, and the V-shaped director increased the antenna gain. The measured impedance bandwidth of the proposed antenna scheme was 75.93%, covering 424-943 MHz, with the measured antenna gain of 2.69-4.84 dBi. The radiation pattern was unidirectional for the entire target operating frequency band. The measured xz-and yz-plane HPBWs were 150°, 159°, and 160° and 102°, 78°, and 102° at 470, 680, and 890 MHz, with the corresponding crosspolarization below −20 dB and −40 dB. In addition, the ABS radome had a negligible effect on the impedance bandwidth and the antenna gain, vis-à-vis the antenna scheme without the ABS radome. The outdoor and indoor testing was also carried out to assess the outdoor and indoor reception performance of the proposed antenna scheme. The power obtained for the outdoor test, at 514 MHz, was 38.4 dBµV (−70.4 dBm) with a C/N of 11.6 dB. Meanwhile, the power obtained for the indoor test was 26.6 dBµV (−82.2 dBm) with a C/N of 10.9 dB. Essentially, the proposed portable wideband directional antenna scheme is operationally suitable for indoor and outdoor digital terrestrial television reception. Moreover, the portable antenna with a radome serves as a home decorative accessory given its modern and stylish design.

Conclusions
This research proposed a portable wideband of a horizontally polarized directional antenna scheme with a radome for digital terrestrial television reception (470-890 MHz). The proposed antenna scheme was adapted from the Yagi-Uda antenna, consisting of a folded bowtie radiator, semicircular corrugated reflector, and V-shaped director. The radome was of thin cylindrical ABS material. Simulations were carried out to optimize the antenna parameters. An antenna prototype was fabricated, and experiments were undertaken to determine the antenna performance. The performance metrics included the impedance bandwidth (|S 11 | ≤ −10 dB), gain, and unidirectionality. The results indicated that the folded bowtie radiator enhanced the impedance bandwidth of the antenna. The corrugated reflector improved the impedance bandwidth and unidirectionality, and the V-shaped director increased the antenna gain. The measured impedance bandwidth of the proposed antenna scheme was 75.93%, covering 424-943 MHz, with the measured antenna gain of 2.69-4.84 dBi. The radiation pattern was unidirectional for the entire target operating frequency band. The measured xz-and yz-plane HPBWs were 150 • , 159 • , and 160 • and 102 • , 78 • , and 102 • at 470, 680, and 890 MHz, with the corresponding crosspolarization below −20 dB and −40 dB. In addition, the ABS radome had a negligible effect on the impedance bandwidth and the antenna gain, vis-à-vis the antenna scheme without the ABS radome. The outdoor and indoor testing was also carried out to assess the outdoor and indoor reception performance of the proposed antenna scheme. The power obtained for the outdoor test, at 514 MHz, was 38.4 dBµV (−70.4 dBm) with a C/N of 11.6 dB. Meanwhile, the power obtained for the indoor test was 26.6 dBµV (−82.2 dBm) with a C/N of 10.9 dB. Essentially, the proposed portable wideband directional antenna scheme is operationally suitable for indoor and outdoor digital terrestrial television reception. Moreover, the portable antenna with a radome serves as a home decorative accessory given its modern and stylish design.