Circularly polarized GPS antenna for simultaneous LHCP and RHCP reception with high isolation
01 Nov 2016-pp 1-4
TL;DR: In this article, a compact dual-feed Global Positioning System (GPS) antenna for simultaneous left and right hand circularly polarized wave reception is presented, which consists of a single patch antenna on top of a printed circuit board and two aperture coupled feeds in the ground plane which are used to generate both left- and right-hand (LH and RH) circular polarizations for the patch.
Abstract: In this paper a compact dual-feed Global Positioning System (GPS) antenna for simultaneous left- and right hand circularly polarized wave reception is presented. The antenna structure consists of a single patch antenna on top of a printed circuit board and two aperture coupled feeds in the ground plane which are used to generate both left- and right-hand (LH and RH) circular polarizations for the patch. The feed network is implemented as a 2-section branch-line coupler underneath the ground plane. It is able to generate adequate phase shifts for both LH and RH circular polarizations simultaneously via two feed ports. Due to the aperture coupling and coupler implementation three layer printed circuit board approach is used. The measured axial ratio is < 1.35 for both polarizations over the 24 MHz bandwidth at the frequency of 1.575 GHz. The isolation between the LH and RH feed ports in reception mode is −35… −26 dB in the broadside direction. The antenna enables simultaneous direct and multipath signal measurement with equal spatial coordinates for both polarizations.
Citations
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19 Mar 2017
TL;DR: Results show good correlation ofSNR's between same sub environments for different satellite elevation ranges which offer useful insight to regenerate a generalized set of SNR parameters in the laboratory environment for the development of 3D GNSS channel model.
Abstract: In this paper, a data classification method for analyzing the aspects of Signal-to-Noise Ratio (SNR) for Global Navigation Satellite System (GNSS) in real conditions is introduced Different parts of measured environments and the orbital information of satellites are used as criteria for data classification It consists of: 1) taking fish eye images of measured routes; 2) dividing measured environments into four potential sub environments (open area, forest area, single building blockage, and street canyon); 3) classifying satellites into nine different groups as function of elevation angles; and 4) creating a table containing the information of mean and standard deviation of SNR for different environments and satellite elevation angles Results show good correlation of SNR's between same sub environments for different satellite elevation ranges which offer useful insight to regenerate a generalized set of SNR parameters in the laboratory environment for the development of 3D GNSS channel model
8 citations
TL;DR: An isolation technique, which does not require conventional circulators, is proposed for the realization of a simple and low-cost aperture-coupled circularly polarized antenna for application to full-duplex devices.
Abstract: An isolation technique, which does not require conventional circulators, is proposed for the realization of a simple and low-cost aperture-coupled circularly polarized antenna for application to full-duplex devices. The approach is based on the use of slotlines loops to provide surface current cancellation in specific regions of the antenna structure, leading to improved axial ratio and isolation between the ports in excess of 50 dB. Circular polarization is achieved by introducing a double-box hybrid coupler, which is optimized to obtain good matching and isolation of the quadrature signals. On this basis, both right- and left-hand circularly polarized beams are achieved by interchanging the transmitting and receiving antenna ports, enabling full-duplex operation and reconfigurability. While the antenna structure is designed for 2.45 GHz operation, one can take advantage of the proposed approach to tune the frequency of maximum isolation. Both single-element prototypes as well as a $2\times 2$ array are fabricated and measured, showing good agreement with the simulations and validating the proposed isolation approach. The beam steering capabilities as well as the application to a Van Atta retrodirective antenna array and the possibilities of achieving delta and sum patterns for monopulse operation are also reported. The proposed full-duplex antenna can also represent an excellent solution for narrowband wireless power transmission systems.
7 citations
Additional excerpts
...The utilization of microstrip hybrid couplers [11] and other feeding geometries, such as in [13], have also been investigated and discussed....
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06 Apr 2017
TL;DR: In this article, a polarization reconfigurable microstrip patch antenna for satellite communication is presented, which consists of a slotted circular patch antenna (SCP), and a reconfigured Branch line coupler as the feed network.
Abstract: This manuscript presents a polarization reconfigurable microstrip patch antenna for Satellite communication It consists of a slotted circular patch antenna (SCP), and a reconfigurable Branch line coupler as the feed network The antenna using reconfigurability can change its polarization among linear polarization (LP), left-hand circular polarization (LHCP), and right-hand circular polarization (RHCP), achieving uplink and downlink frequency bandwidth of 15 GHz in satellite X-band used by military and government institutions
5 citations
TL;DR: In this paper , the authors proposed a two-port MIMO antenna for 28 GHz mm-wave applications, which has compact size, simple geometry, wideband, high gain, and offers circular polarization.
Abstract: This article presents the circularly polarized antenna operating over 28 GHz mm-wave applications. The suggested antenna has compact size, simple geometry, wideband, high gain, and offers circular polarization. Afterward, two-port MIMO antenna are designed to get Left Hand Circular Polarization (LHCP) and Right-Hand Circular Polarization (RHCP). Four different cases are adopted to construct two-port MIMO antenna of suggested antenna. In case 1, both of the elements are placed parallel to each other; in the second case, the element is parallel but the radiating patch of second antenna element are rotated by 180°. In the third case, the second antenna element is placed orthogonally to the first antenna element. In the final case, the antenna is parallel but placed in the opposite end of substrate material. The S-parameters, axial ratio bandwidth (ARBW) gain, and radiation efficiency are studied and compared in all these cases. The two MIMO systems of all cases are designed by using Roger RT/Duroid 6002 with thickness of 0.79 mm. The overall size of two-port MIMO antennas is 20.5 mm × 12 mm × 0.79 mm. The MIMO configuration of the suggested CP antenna offers wideband, low mutual coupling, wide ARBW, high gain, and high radiation efficiency. The hardware prototype of all cases is fabricated to verify the predicated results. Moreover, the comparison of suggested two-port MIMO antenna is also performed with already published work, which show the quality of suggested work in terms of various performance parameters over them.
5 citations
DOI•
TL;DR: In this article , a design approach to a planar dual-sense bidirectional circularly polarized (CP) antenna is presented, which can exhibit orthogonal CP radiations in arbitrary directions between 90° to 180°.
Abstract: A design approach to a planar dual-sense bidirectional circularly polarized (CP) antenna is advanced. The resultant antenna can exhibit orthogonal CP radiations in arbitrary directions between 90° to 180°, i.e., the flared angle formed by pure left-handed CP (LHCP) and right-handed CP (RHCP) directions could be set in a wide range from 90° to 180°. The operational principle is revealed by an equivalent source model at first. Then, prototype antennas are advanced by incorporating a high order mode resonant, V-shape dipole to a planar magnetic dipole and a parasitic electric dipole. As numerically simulated and experimentally validated, the flared angle formed by LHCP and RHCP directions can be adjusted as 90°, and 135°. In the 90° case, the presented bidirectional CP antennas can exhibit impedance bandwidth of 6.6%, 3dB axial ratio (AR) bandwidth of 13.0% in +x-axis and 8.9% in +z-axis. The advanced low-profile (height < 0.05-wavelength) antenna can simultaneously provide spatial and polarization diversity ability in one principal-cut elevation plane. Therefore, it would be a promising colocated, spatial/polarization diversity antenna in future wireless systems.
3 citations
References
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TL;DR: In this article, an analysis of four-arm symmetrical networks such as a branched directional double stub coupler or the hybrid ring (rat race) is presented, where the input wave is broken into an even and an odd mode and the vector amplitude out the various arms is computed from the sums or differences of the reflection or transmission coefficients for the two modes.
Abstract: An analysis of four-arm symmetrical networks such as a branched directional double stub coupler or the hybrid ring (rat race) is presented. The input wave is broken into an even and an odd mode and the vector amplitude out the various arms is computed from the sums or differences of the reflection or transmission coefficients for the two modes. A zero decibel directional coupler is described and its possible use as a duplexer is proposed. The design of multiple stub directional couplers for any degree of coupling is discussed. A method of computing the bandwidth of all these couplers is outlined, and the bandwidth curves, the power out the various arms with respect to frequency of the zero decibel coupler, are computed. A tabulation is made for six different 3 db couplers (even-power split) and their standing wave ratio, evenness of power split and isolation of the fourth arm as a function of frequency assuming perfect performance at the band center.
471 citations
"Circularly polarized GPS antenna fo..." refers methods in this paper
...In this paper, the presented approach of the dual circularly polarized receiver antenna is based on the utilization of a 4-port branch-line coupler [6] as a feeding network for the aperture coupled patch antenna with two symmetrical feeds....
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...adequate bandwidth (BW) a 2-section branch-line coupler is used [6]....
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TL;DR: In this article, the design and testing of an aperture-coupled circularly polarized antenna for Global Positioning System (GPS) applications is described, which operates at both the L1 and L2 frequencies of 1575 and 1227 MHz.
Abstract: This paper describes the design and testing of an aperture-coupled circularly polarized antenna for Global Positioning System (GPS) applications. The antenna operates at both the L1 and L2 frequencies of 1575 and 1227 MHz, which is required for differential GPS systems in order to provide maximum positioning accuracy. Electrical performance, low-profile, and cost were equally important requirements for this antenna. The design procedure is discussed, and measured results are presented. Results from a manufacturing sensitivity analysis are also included.
396 citations
"Circularly polarized GPS antenna fo..." refers background in this paper
...The 3 dB power division, which is a one characteristic of the coupler, has been shown to generate a good circularly polarized (CP) patch antennas in [7]....
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TL;DR: The article analyzes and compares the performance of different GPS antenna designs and finds that a successful conical spiral antenna design is a good choice for the DGPS ground station.
Abstract: The FAA decision allowing the use of the global positioning system (GPS) as a radio navigation and landing help system in the United States commercial airports boosts the need for a high-performance GPS receiver which provides the demanded precision. The design of the receiving antenna is one of the most important parts in the design process, as it has to face significant challenges including uniform coverage of all satellites and the rejection of the multipath signals. The rejection of the multipath signals is accomplished by specifying restrictive criteria to the GPS antenna. This includes a high rejection of the cross-polarized signals and a radiation pattern with a sharp slope for low-elevation angles; that is, near the horizon. The feasibility of using different types of antennas to satisfy restrictive criteria such as dual-frequency coverage (L1 and L2 frequencies), -15 dB cross-polarization rejection, and a beamwidth of more than 130/spl deg/ is discussed. The antenna designs examined in this study include patch antennas, helical antennas, and conical spiral antennas. Two different receiver designs were also examined including a single-antenna system with a hemispherical coverage and an antenna array which may provide independent sectoral coverage or the desired beamwidth. It is shown that a design based on a conical spiral antenna backed with absorbing material may be used to satisfy all the desired specifications. This result was confirmed experimentally.
97 citations
"Circularly polarized GPS antenna fo..." refers background in this paper
...Another study [8] has been performed to find good antenna candidates for the airport radio navigation and landing help system with low crosspolarization levels and the wide beamwidth (>130◦)....
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10 Apr 2016
TL;DR: It is concluded that the polarization based measurement system is able to separate LOS and NLOS signal components thus enabling first steps toward the three-dimensional GNSS channel model development.
Abstract: In this paper, the principle of a polarization-based measurement system intended for the data recording of the Global Navigation Satellite System (GNSS) signals is described. The measurement arrangement includes left- and right hand circular polarized antennas with separate satellite RF recorders for both polarizations. Based on the recorded data for different antenna polarizations the Line-Of-Sight (LOS) and the reflected Non-Line-Of-Sight (NLOS) signal components can be analyzed in order to generate a three-dimensional channel model. Initial field measurements are performed for a route of one kilometer in a university campus area. The initial recorded data include digitized RF signals for all visible Global Positioning System (GPS) satellites, the National Marine Electronics Association (NMEA) data, video recording of the environment and reference velocity from a separate speed sensor. In this paper, the preliminary analysis of the recorded data is presented. Based on the recorded data it is concluded that the polarization based measurement system is able to separate LOS and NLOS signal components thus enabling first steps toward the three-dimensional GNSS channel model development.
9 citations
"Circularly polarized GPS antenna fo..." refers methods in this paper
...Our previous study [3] has been done using two conical spiral antennas [5] with a distance of 0....
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...Our recent measurement campaign for 3D GPS channel model development is based on the simultaneous use of left- and right hand circularly polarized (LHCP and RHCP) antennas [3]....
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08 Aug 2016
TL;DR: Results show that satellite elevation angle, and multipath propagation affect both the position precision measured by the receiver and SNR, and will serve as basis for the development of 3D GNSS channel model to work for both static and dynamic environments.
Abstract: The performance evaluation of Global Navigation Satellite System (GNSS) device in 3D laboratory measurement environment is gaining increasing importance. Even though GNSS is a mature technology the 3D channel model to be implemented in laboratory environment does not exist due to the challenges encountered in creating controllable and repeatable multipath conditions. This research work is a first step toward the one solution of these problems. In this paper, the GNSS data set recorded with the polarization based measurement system is analyzed. Both Right Hand Circularly Polarized (RHCP) and Left Hand Circularly Polarized (LHCP) antennas are employed so that direct and reflected signals can be acquired simultaneously. The goal of the study is to investigate the characteristics of polarization based reflections, path length of delayed multipath signal, position error, coverage efficiency (mean number of tracked satellites), and the impact of satellite elevation angle on received Signal-to-Noise Ratio (SNR) for a typical multipath environment. Results show that satellite elevation angle, and multipath propagation affect both the position precision measured by the receiver and SNR. Additionally, presented results will serve as basis for the development of 3D GNSS channel model to work for both static and dynamic environments.
7 citations