Single Feed Based Wide Band Circularly Polarized Radiating Element For S-band SATCOM

It is well-known that the circular polarization (CP) bandwidth of a microstrip antenna is greatly related to its impedance characteristic. Several broadband antenna structures have been proposed and studied, such as using a thick substrate with low permittivity and a multi-resonator structure. Another method to enhance the impedance bandwidth is using slot antennas instead of the microstrip antennas. In this paper, a new CP design developed from the ring slot antenna is proposed. The antenna structure composed of a wide slot and a parasitic patch is with wideband characteristics. By adjusting the distance between the wide respectively, which are obviously higher than that of a same-size microstrip antenna. Also, the CP designs of wide slot antennas have been investigated to further improve the CP bandwidth. By protruding a T-shaped [3] or an L-shaped strip [4] from the ground plane, the CP bandwidth of the wide slot antenna can reach to 18 %. However, the available designs for the slot antenna with more than 20 % CP bandwidth are relatively few in the open articles. In this paper, a new CP design developed from the ring slot antenna is proposed. The antenna structure composed of a wide slot and a parasitic patch is with wideband characteristics. By adjusting the distance between the wide slot and parasitic patch, the CP bandwidth can be varied between 5 and 45%. Details of the proposed designs and the obtained results are shown and discussed.

A wideband circularly polarized (CP) rectangular dielectric resonator (DR) parasitically coupled to a printed rectangular loops is presented. The DR is housed in a thin dielectric substrate with a microstrip line and narrow strip printed from one side and a ground plane and conducting loops and lines connected to the ground plane. The DR is linearly polarized, and for CP, we introduced printed conducting loops in the other side of the DR, which produce the orthogonal polarization with the required quadratic phase. Several loops are used to achieve the wide CP band. The final design achieves CP with 51% bandwidth. The reflection coefficient, axial ratio (AR), radiation patterns, gain, and efficiency of the antenna are studied, and reasonable agreement between the measured and simulated results is observed.

A novel single‐feed wide band planar single layer circularly polarised (CP) slot antenna is presented. This low cost slot antenna consists of an L‐shaped feeding stub with metamaterial inspired complementary split ring resonator (MICSRR) and a wide 45° rotated symmetric square aperture. Broadband impedance and CP radiation bandwidth (BW) is achieved by using a novel artificial exciting stub with defecting CSRRs on it. By controlling the excitation phase of L‐shaped stub, a desirable circular polarisation can be generated and both impedance and CP BWs are considerably increased by up to 89%. The operating frequency ranges in S/C band about 1.5 octaves from 2.4–6.22GHz that covers most of the commercial wireless communication systems, such as WLAN (IEEE 802.11 (2.4/3.6/4.9/5/5.9GHz)), LTE and WiMAX (2.5/3.5/5.8GHz). The measured BWs of 3‐dB axial ratio and voltage standing wave ratio < 2 are around 91% (2.4–6.4GHz) and 89% (2.4–6.22GHz), respectively. The measured boresight gain is less than 6 dBic over the CP BW.

A novel circularly polarized (CP) microstrip antenna is introduced. The antenna is fed with a single coaxial probe and the structure is planar. The CP bandwidth is much larger than available single-probe microstrip antennas and the CP radiation quality is excellent over the entire upper hemisphere.

A novel single-feed wide band planar circularly polarized (CP) slot antenna is presented. This slot antenna consists of an L-shaped feeding stub with metamaterial inspired complementary split ring resonator (MICSRR) and a wide 45° rotated square aperture. Broadband impedance and CP radiation bandwidth (BW) is achieved by using a novel artificial exciting stub with defecting CSRRs on it. By controlling the excitation phase of L-shaped stub, a desirable circular polarization can be generated and both impedance and CP BWs are considerably increased by up to 89%. The operating frequency ranges in S/C band from 2.4–6.22 GHz. The measured bandwidths of 3-dB axial ratio (AR) and VSWR<2 are around 91% (2.4–6.4 GHz) and 89% (2.4–6.22 GHz), respectively.

This article presents a novel, compact, single feed circularly polarized (CP) microstrip antenna. Proposed design involve an inverted Y‐shaped radiating patch fed by an L‐shaped microstrip line feed and a rectangular open‐loop placed near its right corner. A semi‐rectangular ground plane is used on the opposite side of the substrate. Coupling between the rectangular open‐loop and the inverted Y‐shaped patch plays a vital role in attaining wideband CP, while the semi‐rectangular ground plane is crucial for enhancing impedance bandwidth (IBW). The optimized design achieved measured wide IBW of 5.164 GHz (65.53%, spanning over 5.297‐10.461 GHz) having its center frequency (frc) at 7.878 GHz. The corresponding measured axial ratio bandwidth (ARBW) obtained inside the measured IBW curve is 2.25 GHz (having its center CP resonating frequency fcp 7.52 GHz, spanning over 6.40‐8.65 GHz, 29.92%). Measurement results are validated in both Ansys Electronics Desktop 2020 R1 and CST Microwave Studio 2018. Proposed antenna is fabricated on FR‐4 epoxy substrate of 1.6 mm thickness and exhibits a very small footprint of just 400 mm2 (20 × 20 mm2) (size 0.58λmgL × 0.58λmgL × 0.046λmgL, where λmgL is the measured guided wavelength at lower resonating frequency fmrL = 5.297 GHz) with 51.31% reduction in size. Measured maximum peak gain for the impedance band is 2.04 dBi at 8.8 GHz and 1.96 dBi at fcp 7.52 GHz. The structure of the proposed antenna is extremely simple, quite small in size and its CP bands can be suitable for some C‐band and ITU (International Telecommunication Union)—8 GHz application.

ABSTRACTIn this paper, two circularly polarised (CP) antennas are proposed. One is dual band CP (DBCP) while the other is wideband CP (WBCP). Both the slot antennas are coplanar waveguide-fed corner truncated structure with an L-shaped radiating patch. The CP bandwidth is significantly improved by connecting one end of the L-shaped patch to the ground plane which also resulted in miniaturisation of the antenna with a size of 48 × 43 mm. DBCP is generated by adding an extra rectangular stub to the ground plane while WBCP by cutting two additional slots in the ground plane. The dual band antenna has a measured impedance bandwidths (S11 < −10 dB) of 34% (2.2–3.1 GHz) and 42% (4.6–7.1 GHz) while the corresponding 3 dB axial ratio bandwidths (ARBWs) are 34% (2.2–3.1 GHz) and 28.6% (4.8–6.4 GHz). The measured impedance bandwidth and ARBW of the wideband antenna are 102% (2.2–6.8 GHz) and 93% (2.3–6.3 GHz), respectively.

This article presents the first report of a circularly polarized (CP) omnidirectional radiation antenna for wireless capsule endoscope (WCE) system applications. The proposed antenna incorporates an integrated design concept, and achieves operation at 0.915 GHz Industrial, Scientific, and Medical (ISM) band (0.902-0.928 GHz) with a compact size of π×5.5 <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> ×22 mm <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</sup> . The simulation is performed in Ansys HFSS, with the antenna being placed in the center of a cylindrical homogeneous muscle tissue with a size of π×55 <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> ×80 mm <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</sup> . The simulated results show that the capsule antenna has an impedance bandwidth (BW) ( |S <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">11</sub> | <; -10 dB) from 0.82 to 0.99 GHz and a CP BW (AR <; 3 dB) from 0.84 to 1.09 GHz. Moreover, the omnidirectional CP radiation properties remain stable for a very wide θ range (49°-144°) in the elevation plane. The robust CP performance and the integrated design concept make the proposed antenna suitable for advanced WCE systems.

This paper presents, a microstrip feeding structure to generate wideband circular polarization in dielectric resonator antenna. Wideband circular polarization (CP) has been obtained through the use of modified ground plane and three stubs in the microstrip feed line. The designed CP DRA has shown input impedance bandwidth (S <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">11</sub> <;-10 dB) of 70.37% (1.93-4.02 GHz) and axial ratio bandwidth (AR<;3 Db) of 15.28% (2.90-3.38 GHz) in θ = 0°, φ = 0° direction, respectively. It has been observed from CP radiation pattern that the designed antenna shows left-handed CP in θ = 0°, φ = 0° direction. The proposed CP DRA has average radiation efficiency and gain of 89.24% and 1.98 dBic respectively, in broadside direction and it covers entire operating frequency band. The proposed CP DRA is useful for Wi-MAX (3.3-3.6 GHz) and S-band frequency applications. Simulation has been done on HFSS and cross verified with CST-MS software.

This paper presents a method of wideband circular polarization (CP) generation using a stacked patch-ring microstrip antenna with a single probe feed. An enhanced axial ratio (AR) bandwidth is obtained when a combination of a square ring and a square patch with negative perturbations is used as parasitic and driven elements, respectively. The axial ratio bandwidth obtained is significantly larger compared to the case when square rings are used as parasitic and driven rings with a single feed. A simulated impedance bandwidth (Sn< −10dB) of 16%, 3dB AR bandwidth of 8%and a peak gain of 8.65 dBic are obtained from this antenna.

This paper presents the design of a novel reflective linear-to-circular polarization conversion metasurface (PCM) and its application to a wideband high-gain circularly polarized (CP) antenna. The proposed PCM efficiently converts incident linearly polarized (LP) waves into CP waves within an ultra-wideband range of 11.8-28.6 GHz, thereby laying a solid foundation for the design of the wideband CP antenna. By adding an LP microstrip antenna as the feed source above the PCM, the metasurface leverages its polarization conversion capability to reflect CP waves, simultaneously enhancing the antenna gain, and thus yields a wideband high-gain CP antenna. The designed CP antenna exhibits an impedance bandwidth and a 3-dB axial ratio (AR) bandwidth both spanning from 13.2 to 18.6 GHz, corresponding to a relative bandwidth of 34%. Notably, the 3-dB AR bandwidth perfectly matches the impedance bandwidth. Meanwhile, the antenna maintains a stable high gain exceeding 11 dBi across the entire operating bandwidth. Excellent agreement is achieved between the measured and simulated results, confirming that the proposed antenna simultaneously achieves a wide CP operating bandwidth, full-band 3-dB AR coverage, and high gain. Such characteristics make it highly valuable for potential applications requiring both wideband CP operation and high gain, such as microwave communications, precision radar, and satellite navigation systems.

A reconfigurable design is proposed to improve the circular polarization (CP) operating bandwidth of an annular‐ring slot antenna fed with an L‐shaped coupling strip.The design involves four voltage‐controlled varactor diodes, which are placed below the slot and symmetrically distributed along the circumference of the slot. When all antenna dimensions remain constant, the CP operating frequency of the slot antenna can be decreased by varying dc voltage values. In addition, theses CP operating frequencies, which are corresponding to different dc voltage values can form a successive frequency band, and the available CP bandwidth is thus improved. Experimental results indicate that with the reconfigurable design, the 3‐dB axial‐ratio CP bandwidth can be increased by a factor of 4 for the annular‐ring slot antenna with a reflector. © 2010 Wiley Periodicals, Inc. Microwave Opt Technol Lett 52: 1377–1380, 2010; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.25192

A fully metallic radiating element is presented in this article for single and dual circular polarization applications. The shape of the radiating element corresponds to a bow-tie-shaped field rotator designed to generate two orthogonal modes in quadrature as a basis for circular polarization. The bow-tie-shaped basic element is able to provide low axial ratio with a compact, easy-to-manufacture profile. In addition, it allows diverse ways of operation: feeding through a rectangular waveguide provides single circular polarization, while square waveguide is used for dual circular polarization. The radiating element has been designed at the Ku band and validated by the competitive experimental results. In the case of single circular polarization, over 21% bandwidth has been obtained under 15 dB return loss and 3 dB axial ratio criteria, with a radiating element height of $0.75 {\lambda }_{0}$ (free-space wavelength) at 18 GHz. The dual circularly polarized version achieves 18.3% bandwidth when 15 dB return loss and 3 dB axial ratio are established. In this case, the required antenna height is slightly higher than ${\lambda }_{0}$ at 18 GHz.

In this Letter, a fork-shaped wideband circularly polarised antenna is proposed. Using the fork-shaped metal wall structure and 45° deflection, the wideband circular polarisation performance of the proposed antenna is achieved. Besides, an antenna prototype working at W-band is processed. The right-hand circularly polarised bandwidth (axial ratio < 3 dB) and impedance bandwidth (S11 < −10 dB) of the antenna are both measured as 38.1% (75–110 GHz). The measured gain is 10.7–14.2 dBic (±0.5 dBic). The proposed antenna exhibits a simple structure, which is easy to process. This proposed wideband circularly polarised horn antenna can have wide applications for millimetre and sub-millimetre wave bands.

A new technique to design single-feed circularly polarized (CP) microstrip antenna is proposed. The CP radiation is obtained by adjusting the dimension of the etched fractal defected ground structure (FDGS) in the ground plane. Parameter studies of the FDGS are given to illustrate the way to achieve CP radiation. The CP microstrip antennas with the second and third iterative FDGS are fabricated and measured. The measured 10-dB return-loss bandwidth of the CP microstrip antenna is about 30 MHz (1.558 to 1.588 GHz), while its 3-dB axial-ratio bandwidth is 6 MHz (1.572 to 1.578 GHz). The gain across the CP band is between 1.7 and 2.2 dBic.