Compact Right‐Handed Circularly Polarized V‐Shaped Patch Array Antenna for Nanosatellites

Compact circularly polarized rectangular dielectric resonator antenna (CPRDRA) using wideband branch line coupler (WBLC) is investigated for navigational satellite applications. In this paper, a footprint area of CPRDRA is reduced using high dielectric constant dielectric resonator (e r = 20.40) and high dielectric constant dielectric substrate (Rogers R03210 e r = 10.2). The area of compact CPRDRA is 25 x 25 mm2 which is designed to operate in frequency range of 2.48 to 2.5 GHz with resonant frequency of 2.49 GHz. The return loss, right hand circular polarization (RHCP) realized gain and axial ratio are simulated using ANSYS HFSS14.0. Simulated return loss is better than 24 dB in the operating frequency band. RHCP in CPRDRA is generated using wideband branch line coupler. The RHCP gain in CPRDRA are stronger than the left hand circular polarization (LHCP) gain by 24 dB in broadside direction. RHCP realized gain of CPRDRA is 2.9 dB at zenith. Axial ratio of compact CPRDRA is better than 3 dB at zenith to ±48° for phi=0, 45 and 90 degrees. Verification of DRA simulation using ANSYS HFSS is done by comparing our results with CPDRA results reported by Fang, Leung and Lim [8]. Experimental results will be reported for compact CPRDRA regarding return loss, antenna gain and axial ratio.

Compact dual band circularly polarized rectangular dielectric resonator antenna (CPRDRA) using dual section Wilkinson power divider (DSWPD) with wideband 90° phase shifter is investigated for Indian Regional Navigation Satellite System (IRNSS) applications. In this paper, a ground plane area of dual band CPRDRA is miniaturized using high dielectric constant ε <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">r</sub> = 51.92 of ceramic dielectric resonator and high dielectric constant ε <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">r</sub> = 10.2 of Rogers R03210 dielectric substrate. The compact ground plane area of dual band CPRDRA is 40 x 40 mm <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> and is designed to operate in L5-band- 1.164 to 1.188 GHz with lower band resonant frequency of 1.176 GHz and L1-band- 1.565 to 1.585 GHz with upper band resonant frequency of 1.575 GHz. The simulation and measurement of dual band CPRDRA return loss (RL), right hand circular polarization (RHCP)-left hand circular polarization (LHCP) realized gain and axial ratio (AR) are given in this paper. Simulated and measured RL is better than 10 dB in L5-L1 bands. RHCP in dual band CPRDRA is generated using DSWPD with wideband 90° phase shifter. In broadside direction, dual band CPRDRA RHCP realized gain is higher than the LHCP realized gain by 20 dB. The dual band CPRDRA RHCP realized gain is 1.7 dB at zenith. The compact dual band CPRDRA AR is better than 3 dB from zenith to ±45° at phi=0°, 45° and 90°.

This paper presents a new approach to implement planar shared-aperture dual-band dual-circular polarization (CP) array antennas. The antennas can be fabricated on a single-layer substrate and extended to a larger array easily. In this approach, each array element is obtained by connecting two patches working at different frequencies directly. To form arrays with higher gain, two kinds of feed networks are described, which can be applied in systems where narrowband and wideband are needed, respectively. One is using the conventional feed network and the other is using the sequential rotation technique to further improve the CP axial ratio (AR) performance. Two prototype arrays with $4 \times 4$ elements are fabricated and tested in $X/Ku$ bands. Experimental results show that good CP characteristics are obtained, which agree well with the simulation results. For the first narrow-band prototype array, the 3-dB AR bandwidth is around 1.5% for both bands. For the second array using the sequential rotation technique, the bandwidth of return loss and AR are wider. In the lower band centered at 12.1 GHz, the ${-}10\hbox{-}\text{dB}$ return loss bandwidth is 8.3% and the 3-dB AR bandwidth is 14.2% [right-hand CP (RHCP)]; in the higher band centered at 17.4 GHz, the corresponding data are 18.9% and 14.9% [left-hand CP (LHCP)], respectively.

LHCP and RHCP analysis of microstrip patch antenna at 5.2 GHz has been discussed in this work. A linearly polarized coaxial fed microstrip patch antenna has been modeled in ANSYS HFSS. To analyze the Left Hand Circular Polarization(LHCP) and Right Hand Circular Polarization (RHCP) Patch structure is modified respectively. To differentiate between LHCP and RHCP Field analysis and Gain analysis has been done. All the three microstrip patch antennas modeled on 1.6 mm thick FR4 substrate with the Dielectric constant 4.4. For the designed microstrip patch antennas return loss, gain and axial ratio observed. For linearly polarized microstrip patch antenna axial ratio is 63dB and for circularly polarized microstrip patch antenna axial ratio less than 2dB observed. For LHCP microstrip patch antenna LHCP Gain approximately 20dB greater than RHCP Gain and for RHCP microstrip patch antenna RHCP Gain approximately 20dB greater than LHCP Gain is observed. Fabrication of linearly polarized antenna and LHCP antenna has done. measured return loss and VSWR results compared with the simulated antenna results.

In this paper, a dual polarization patch antenna operates at the wide bandwidth of 1.525GHz∼1.665GHz was designed and fabricated. To obtain the wide bandwidth and high gain, increas ed height of air floor from GND was applied, and to get wide band axial ratio and high gain, parasitic patch was applied. The simulation and measurement showed good agreements, the VSWR was less than 1.9 at the frequency bandwidth, the return loss was less than –10dB, and the LHCP(Left Hand Circular Polarization) and RHCP(Right Hand Circular Polarization) isolation was less than –13dB at the frequency bandwidth.

This paper proposed a right-handed circularly polarized (RHCP) micro-strip antenna for multi-navigation system applications. The size of the antenna is 70 mm × 70 mm × 2 mm, which is fabricated on an FR4 substrate. A meandering technique on a patch layer and asymmetrical defected ground structures (DGS) are employed to achieve the purpose of miniaturization and increase the bandwidth of the axial ratio. The prototype of this antenna is fabricated according to simulations where the bandwidth of return loss, bandwidth of axial ratio, and radio pattern are further testified. The bandwidth of return loss (S11) and axial ratio (AR) of the antennas are from 1.540 GHz to 1.612 GHz and 1.554 GHz to 1.601 GHz, which would be available for L1 of GPS, L1 of SBAS, E1 of Galileo as well as B1I and B1C of BDS-3, the last two of which can be used for aircraft tracking. The relative bandwidth is 2.98%, which satisfies the standard of wide-band patch antennas.

A RHCP (Right Hand Circular Polarization) microstrip array antenna with EBG structures is designed and optimized. Compared with a conventional RHCP microstrip array antenna, the proposed antenna accomplishes high isolation up to −28dB. High isolation is achieved by simultaneously implementing mushroom-like electromagnetic gap band (EBG) structures, which operate in the same frequency range with the microstrip antenna. To validate our design method, comprehensive simulation has been done. Furthermore, both the return loss and axial ratio bandwidth of the proposed antenna cover the ETC operating band (5.75 GHz to 5.84 GHz) in China.

In this communication, two wideband dual-polarized dielectric resonator antennas (DRAs) for X-band radar applications are presented. The design procedure is started with designing a linear polarized DRA fed by a microstrip line. The feedline is optimized to excite the hybrid electromagnetic (HEM) <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$_{11 \delta }$ </tex-math></inline-formula> modes of DRA which corresponds to magnetic monopole-like radiation. Then, a novel quadrature hybrid is designed in the feeding structure to provide both left-hand circular polarization (LHCP) and right-hand circular polarization (RHCP). Finally, two antenna prototypes are fabricated and tested: a dual (right hand and left hand) circular polarization DRA with omnidirectional pattern and an enhanced gain version of dual-polarized circular polarized (CP) DRA with a directive pattern. The measurement results of antennas confirm wideband impedance bandwidth (34% and 38.8%) as well as wideband axial ratio (AR) ones (23% and 30%) in element and array structures, respectively. The antennas also provide both RHCP and LHCP radiation. The first antenna contains monopole-like radiation which is aimed at wireless systems with omnidirectional pattern requirements. The second antenna, a <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$2\times 1$ </tex-math></inline-formula> antenna array, presents around 9 dB across the entire band. The presented antennas are good candidates for radar applications such as weather monitoring, air traffic control, and vehicle speed detection.

A circular polarization (CP) and mode reconfigurable wideband orbital angular momentum (OAM) patch array antenna is presented. The proposed design is based on a reconfigurable feed network (RFN), a direct current (dc) bias circuit, and a <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$2 \times 2$ </tex-math></inline-formula> patch array. By changing the dc bias voltages of p-i-n didoes, the operating state of the antenna can be reconfigured between the left-hand CP with a mode <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$l = +1$ </tex-math></inline-formula> and right-hand CP (RHCP) with a mode <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$l = -1$ </tex-math></inline-formula> , over the wide impedance bandwidth of 21%. For the two states, the measured peak gains are larger than 5.3 and 5.2 dBi, and the axial ratios in half-power main beam directions are lower than 1.29 and 1.05 dB, respectively. Different from existing OAM antennas, the diversities of polarization, frequency, and mode, as well as the CP with inherently high cross-polarization discrimination are simultaneously integrated in the proposed antenna, which serves as a good basis for improving the capacity and spectral efficiency of radio systems. In addition, the antenna features single-external input port, a simple RFN occupying a small number of diodes, and a compact size of <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$1.28 \times 1.28 \times 0.07 \lambda _{0}^{3}$ </tex-math></inline-formula> ( <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\lambda _{0}$ </tex-math></inline-formula> is the free-space wavelength at center frequency), all of which ease implementation and reduce fabrication cost. Therefore, the proposed antenna is very promising for modern high-speed and large capacity wireless communication systems.

Miniaturized L1 (1.565-1.585 GHz) and L5 (1.164-1.188 GHz)-band Circular Polarized (CP) Rectangular Dielectric Resonator Antennas (RDRAs) are designed, analyzed, fabricated and tested for navigation satellite applications. Ground plane area of RDRAs are reduced using high dielectric constant (ε <inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">r</inf> = 51.92) dielectric resonator material and dielectric substrate (ε <inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">r</inf> = 10.2). Miniaturized RDRAs are designed at center frequencies 1.575 GHz with ground plane footprint area of 28 mm × 28 mm for L1-band and 1.176GHz with ground plane footprint area of 40 mm × 40 mm for L5-band, respectively. Circular polarization of RDRAs for L1 and L5-band are generated using Wilkinson Power Divider (WPD) with wide-band 90° phase shifter. Broadside radiation patterns of RDRAs for L1 and L5-band are obtained using TE <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">y</sup> <inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">111</inf> mode. Simulated and measured Return Loss (RL) of RDRAs for L1 and L5-band are better than 14 dB. Simulated Right Hand Circular Polarization (RHCP) gain of RDRAs are 2.05 dB for L1 and 1.6 dB for L5-bands, respectively. Simulated Axial Ratio (AR) of RDRAs for L1 and L5-band are found to be lower than 3dB. Measured parameters such as RHCP-LHCP (Left Hand Circular Polarization) radiation patterns, RHCP gain and AR are found to be closed agreement with simulated results.

A compact sequential-rotation array with serial feed and three probes using multi-layer substrate is proposed. The most compact shape for the microstrip patches are selected with the optimization for the axial ratio and return loss bandwidth. The gain, return loss, and axial ratio bandwidths of the antenna are improved significantly by converting three patches to one circular. The patch radius and the position of probes are selected to form circular Poynting vectors around it where the maximum power is present at large frequency range. While the two layers of the structure use similar board this structure only uses a substrate and three simple pins. Also the total area of the antenna is limited to the microstrip patch and it has a straightforward fabrication steps. So the wideband antenna is relatively inexpensive and compact. The antenna has 21.4% 3 dB axial ratio bandwidth in simulation and 21.1% in fabrication. Consequently, the serial-multi-fed circular patch with unique angular and phase arrangements is suitable for many applications as the antenna arrays. © 2014 Wiley Periodicals, Inc. Int J RF and Microwave CAE 24:529-535, 2014.

In this paper, a novel design for wideband high gain Right Hand Circular Polarized (RHCP) 2×4 array antenna at L-Band is presented for data link application. The proposed antenna used for long range highly maneuvering vehicles like missiles which needs high gain and RHCP to provide sufficient link margins. Orthogonal feeding is used for first patch and second patch is electromagnetically coupled to enhance impedance bandwidth. Sequential rotation technique is implemented to improve the Axial Ratio (AR) bandwidth. The antenna is simulated using commercially available software (CST microwave studio). The realized antenna reported 20.2% VSWR bandwidth, 14.64% AR bandwidth. The obtained gain is more than 14.5dBi, El & Az beamwidth of 44° and 20° over frequency band respectively.

A reconfigurable, planar, and end-fire circularly polarized (CP) antenna with wide beamwidth is presented, which exhibits the bidirectional radiation with the same sense by combining two pairs of identical CP elements placed in a back-to-back configuration. The design of the element includes a meandering phase delay line, which connects a printed electric dipole and a quarter-wavelength shorted microstrip patch. Then, eight p-i-n diodes are employed in the two dipoles arms to realize either left-handed CP (LHCP) or right-handed CP (RHCP) by manipulating the DC bias voltage across p-i-n. The prototype is designed to operate at a center frequency of 5.8 GHz with a size of 0.61 × 0.50 × 0.029 (λ03), where λ0 is the wavelength of the center frequency. Also, its end-fire beam is in parallel with its plane. Experimental results show that the overlapped bandwidth for 10-dB return loss and the 3-dB axial ratio (AR) of the bidirectional end-fire antenna is from 5.72 to 5.89 GHz for the two CP states. The half-power beamwidth (HPBW) in the horizontal and vertical plane are 95°/115° at the 5.8 GHz.

A cavity‐backed self‐phased circularly polarized (CP) antenna based on stepped‐width dipoles with wide axial ratio beamwidth is proposed for global positioning system (GPS) applications. The radiator of the antenna consists of two pairs of stepped‐width dipoles, contributing to the CP radiation. The working principle of CP radiation is elaborated by using two simplified models. Then, a feeding network consisting of a Y‐shaped structure and two pairs of identical coplanar striplines (CPSs) is utilized to feed the radiator. Moreover, a cavity‐backed reflector is employed in this antenna to achieve a unidirectional radiation with wide axial ratio (AR) beamwidth. Measured results show that the proposed antenna achieves a wide impedance bandwidth of 43% from 1.37 to 2.12 GHz with Return Loss &gt; 15 dB, and a 3‐dB axial ratio (AR) bandwidth of 6.98% from 1.52 to 1.63 GHz. Particularly, the antenna shows a right‐hand circular polarization (RHCP) radiation with wide 3‐dB AR beamwidth of 205° and 215° in the XOZ and YOZ plane at the center frequency of 1.575 GHz, respectively.

In this paper, we obtain the left-handed circularly polarized (LHCP) and right-handed circularly polarized (RHCP) of triangular array eight patches antennas using corporate feeding-line for circularly polarized-synthetic aperture radar (CP-SAR) sensor embedded on unmanned aerial vehicle (UAV) with compact, simple, and efficient configuration. Although the corporate feeding-line design has already been developed, its design was for the side antenna view of 0° and only produced one of LHCP or RHCP instead of both. Here, the design for LHCP and RHCP eight patches array fed by corporate feeding-line having the side antenna view of 36° at f =1.25 GHz for CP-SAR are discussed. We use the 2016 version of computer simulation technology (CST) to realize the method of moments (MoM) for analyzing. The performance results, especially for gain and axial ratio ( Ar ) at resonant frequency are consecutively 13.46 dBic and 1.99 dB both of LHCP and RHCP. Moreover, the 12-dBic gain-bandwidth and the 3-dB Ar -bandwidth of them are consecutively around 38 MHz (3.04%) and 6 MHz (0.48%). Furthermore, the two-beams appeared at boresight in elevation plane for average beamwidth of 12 dBic-gain and the 3 dB- Ar LHCP and RHCP have similar values of around 12° and 46°, respectively.