Dual-polarized Microstrip Antenna Research Articles

Dual-Feed Dual-Polarized Patch Antenna With Low Cross Polarization and High Isolation

A dual-feed dual-polarized microstrip antenna with low cross polarization and high isolation is experimentally studied. Two different feed mechanisms are designed to excite a dual orthogonal linearly-polarized mode from a single radiating patch. One of the two modes is excited by an aperture-coupled feed, which is comprised of a compact resonant annular-ring slot and a T-shaped microstrip feed line; while the other is excited by a pair of meandering strips with a 180deg phase differences. Both the linearly-polarized modes are designed to operate at 2400 MHz frequency band, and from the measured results, it is found that the isolation between the two feeding ports is less than 40 dB across a 10 dB-input-impedance bandwidth of 14%. In addition, low cross polarization is observed from the radiation patterns of the two modes, especially at the broadside direction. Simulation analyses are also carried out to support the measured results.

Design of dual-polarised microstrip antenna with high isolation using capacitive feeds

A new dual-polarised microstrip antenna with high isolation is presented. The high isolation is achieved by using dual capacitive feeds with open-circuited microstrip stubs placed above the radiating patch. The antenna is designed to operate at around 915 MHz for UHF radio frequency identification applications, and experimental results show that it has more than 33.3 dB isolation over the impedance bandwidth of 5.3 .

Compact dual frequency dual polarized cross patch antenna with an X‐slot

AbstractA new design of a compact single‐feed dual frequency dual polarized microstrip antenna with an X‐slot is presented. The proposed antenna generates two orthogonally polarized radiations with center frequencies at 1.42 GHz and 1.79 GHz, respectively. For fixed dual frequency operation, the antenna has an area reduction of 74% and 59% for the respective frequencies compared to standard rectangular patches. The antenna exhibits broadside radiation pattern and has sufficient gain for the two bands. © 2008 Wiley Periodicals, Inc. Microwave Opt Technol Lett 50: 3198–3201, 2008; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.23903

Wideband dual-polarized slot-coupled microstrip array for synthetic aperture radar application

An 8 × 1-element wideband dual-polarized slot-coupled microstrip antenna array with high isolation and low cross-polarization in X-band is presented. The array antenna offers an impedance bandwidth (VSWR≤2) of 23% and 21% for dual polarization ports, respectively. The measured isolation between two polarization ports is better than 35 dB and the measured cross-polarization level below −25 dB in the main beam over the operation frequency band of 9.35 GHz to 9.75 Ghz. This array is well suitable for X-band SAR (synthetic aperture radar) antenna application.

Dual-polarised CPW-fed microstrip antenna for wireless applications at 2.45 GHz

The design and fabrication of a dual-polarised microstrip antenna fed by two coplanar waveguides (CPWs) for operation at 2.45 GHz are presented. Obtained results show an impedance bandwidth of 44.3 MHz using a single layer of substrate. The simulated return loss for both polarisations is less than −35 dB, and the isolation between the ports of the antenna is better than 21 dB.

Design of an S∕X dual-band dual-polarised microstrip antenna array for SAR applications

A novel design of dual-band dual-polarised microstrip antenna arrays for synthetic aperture radar applications with a frequency ratio of about 1:3 is presented. Stacked microstrip dipoles and square patches are used as the radiating elements at S- and X-bands, respectively. The microstrip dipoles are proximately coupled and the square patches are probe-fed. Experimental data show good agreement between simulated and measured results. The measured impedance bandwidth (VSWR≤2) the prototype array reaches 8.9% and 17% for S- and X-bands, respectively, and the measured isolation between polarisations for both bands are better than −20 dB. The measured crosspolarisation level is ≤−26 dB for the S-band and ≤−31 dB for the X-band. The work verifies the practicability of the dual-band dual-polarised microstrip antenna array design, using the combination of microstrip dipoles and patches, and good bandwidth and isolation performance of the prototype array has been achieved.

Broadband printed antennas and dual-polarized microstrip and waveguide slot antenna arrays

In order to meet the urgent needs in wireless communications, microwave image synthetic aperture radars (SAR), and electronic warfare systems, this dissertation studies several types of broadband dual-polarized planar antenna elements and arrays, and proposes a few of novel designs with experimental verification. The main accomplishments reported in the dissertation are as follows.

Dual-band and dual-polarised microstrip antenna

A microstrip antenna with dual-band and dual-polarisation operation, realised by electromagnetically feeding using a microstrip-T junction and CPW-line, is proposed and discussed. Since both ports of the antenna are electromagnetically coupled and separately placed on both layers of a substrate, the proposed antenna eliminates the need for capacitors in the RF path for multi-layered active antenna applications.

Dual-band dual-polarised microstrip antenna array for SAR applications

A novel dual-band dual-polarised microstrip antenna array for synthetic aperture radar applications with a dual-frequency ratio of about 1:3 is presented. Microstrip dipoles and square patches are used as the radiating elements at S- and X-bands, respectively. The measured bandwidth of VSWR<2 reaches 8.9% and 17% for S- and X-bands, respectively. The measured cross-polarisation levels are <−26 dB for the S-band and <−31 dB for the X-band.

Dual-polarized slot-coupled microstrip antenna with very high isolation

A wideband dual-polarized slot-coupled stacked microstrip antenna with very high isolation and low cross-polarization is presented. To improve isolation between two polarization ports, the stacked patches are excited by an open-ended and a T-shaped micros-trip lines both via two H-shaped slots placed in a “T” configuration. The measured isolation is better than 40.5 dB over the bandwidth from 8.8 to 9.8 GHz with cross-polarization level less than −28.5 dB. The measured VSWR⩽2 bandwidths reach 20.7% and 19.1% at the vertical and horizontal polarization ports, respectively. This antenna is suitable to be used as array elements in spaceborne synthetic aperture radars (SAR) and active phased array radars.

Design of a high isolation dual-polarized slot-coupled microstrip antenna

The design of a wideband dual-polarized slot-coupled stacked microstrip antenna with high isolation is introduced. The proposed stacked-patch antenna is excited by both open-ended and T-shaped microstrip lines via two H-shaped slots placed orthogonally so as to improve the isolation between the two polarization ports. The measured isolation is better than 40.5 dB over the bandwidth from 8.8 to 9.8 GHz with cross-polarization level of less than −28.5 dB. The measured VSWR ≤ 2 bandwidths reach 20.7% and 19.1% for the two polarization ports, respectively. This antenna is suitable as an array element for spaceborne synthetic aperture radar (SAR) and active phased-radar applications. © 2005 Wiley Periodicals, Inc. Microwave Opt Technol Lett 47: 212–215, 2005; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.21126

Simple broadband dual-polarized printed antenna

A novel broadband dual-polarized microstrip antenna suitable for array applications is presented. It uses an aperture-coupled feed for one polarization, while a microstrip-line feed with slotted ground plane is used for the other polarization. The antenna can make good use of the space on both sides of the ground plane, as the feed circuits for two orthogonal polarizations are placed on each side of the ground plane, respectively. By using a single patch, the prototype antenna designed at 2 GHz yields a bandwidth of more than 17% at both ports, and isolation below −32 dB. Good broadside-radiation patterns are observed, and the cross-polar levels are below −18 dB at both the E- and H-planes. This antenna will be useful for active phased-array applications as well as polarization-diversity applications where integration with other circuits at each port is needed. © 2005 Wiley Periodicals, Inc. Microwave Opt Technol Lett 46: 144–148, 2005; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.20926

Liquid Crystal polymer (LCP): a new organic material for the development of multilayer dual-frequency/dual-polarization flexible antenna arrays

The development of dual-frequency (14 and 35 GHz), dual-polarization microstrip antenna arrays is presented for the first time on liquid crystal polymer (LCP) multilayer technology. Some of the properties of LCP, such as multilayer (three-dimensional) vertical integration capability, good electrical and mechanical properties, and near-hermetic nature, make this substrate a practical choice for the design of low-cost antenna arrays that can be integrated with remote sensing applications operating in the Ku and millimeter-wave frequency bands. This work illustrates the potential of LCP as a low-cost, "all-package" solution for developing compact, flexible, antenna arrays that can be used in future communication and remote sensing systems.

Dual-polarized slot-coupled planar antenna with wide bandwidth

A new dual-polarized slot-coupled microstrip patch antenna is presented, which can achieve high-isolation, low cross-polarization levels, a wide bandwidth, and low backward radiation levels. The coupling slot is an H-shaped slot. For wide bandwidth and easy integration with active circuits, it uses slot-coupled stacked microstrip patches. The theoretical analysis is based on the finite-difference time-domain (FDTD) method. First, a parametric study on the input impedance of the antenna with a single input port is presented. Based on the results, a dual-polarized microstrip antenna is designed, fabricated, and then measured. The measured return loss exhibits an impedance bandwidth of over 20.9% and the isolation between two polarization ports is better than 36 dB over the bandwidth. The cross-polarization levels in both E and H planes are better than 22 dB. The front-to-back ratio of the antenna radiation pattern is better than 21 dB. Both theoretical and experimental results of return loss, isolation, and radiation patterns are presented and discussed.

Two-element dual-frequency microstrip antenna with high isolation

A compact design of a dual-frequency dual-polarised microstrip antenna structure with highly decoupled input ports is presented. The proposed antenna structure consists of two radiating elements, an annular ring and a circular disk, that are placed concentrically at the same layer. The two radiating elements are fed by an aperture-coupled feed and a coplanar-microstrip-line feed, respectively. Several prototypes of the proposed dual-frequency antennas operated at the frequency ratios ranged from 1.2 to 2.6 were constructed and tested. The experimental results show the input isolation of less than −50 dB is obtained.

Dual‐port dual‐polarized microstrip antenna

AbstractExperimental and simulated results for a dual‐port dual‐polarized microstrip antenna are presented. The antenna excites two orthogonally polarized resonant frequencies providing an isolation of ∼30 dB between the ports. The patch geometry consists of two circular arcs of different radii with their centers displaced by a distance. This new design offers an area reduction of ∼70% compared to a standard rectangular microstrip antenna with a reduction in gain of 1.7 dB. © 2002 Wiley Periodicals, Inc. Microwave Opt Technol Lett 34: 459–460, 2002; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.10494

Dual-frequency dual-polarized slot-coupled compact microstrip antenna for communication systems

A new design of a dual-frequency dual-polarized square microstrip antenna fed along the diagonal, embedded with a square slot having three extended stubs for frequency tuning, is introduced. The proposed antenna was fabricated using a standard photolithographic method and the antenna was tested using the HP 8510C Vector Network Analyser. The antenna is capable of generating dual resonant frequencies with mutually perpendicular polarizations and broad radiation pattern characteristics. Such dual-frequency designs find wide applications in personal mobile handsets combining GSM and CDS 1800 modes, and applications in which different frequencies are used for emission and reception such as personal satellite communications and cellular network systems.

Dual polarization stacked microstrip patch antenna array with very low cross-polarization

This paper describes the development and performance of a wideband dual linear polarization microstrip antenna array used in the Danish high-resolution airborne multifrequency polarimetric synthetic aperture radar, EMISAR. The antenna was designed for an operating frequency of 1.25 GHz/spl plusmn/50 MHz and was built as an array of 8/spl times/2 probe-fed stacked microstrip patches. The feeding network is constructed in microstrip and is capable of handling 6 kW of peak input-power at an altitude of 45000 ft (unpressurized). The impedance bandwidth (return loss better than -14 dB) of the antenna is 10%, the isolation between the horizontal and the vertical ports of the array is 50 dB and the cross-polarization suppression is 40 dB. A new design principle for simultaneously achieving very low cross-polarization and low side lobes in dual linear polarization antenna arrays has been applied.

Dual-polarised wideband microstrip antenna

A dual-polarised aperture-coupled microstrip antenna with a wide bandwidth, a high isolation, low cross-polarisation levels and low backward radiation levels is presented. The square patch is fed at two corners via H-shaped apertures. The measured return loss exhibits a bandwidth of over 24.4% and the isolation is better than 30 dB over the bandwidth. The cross-polarisation levels and the front-to-back ratio are better than -23 and 22 dB, respectively.

Wideband dual-polarised microstrip patch antenna

A dual-polarised microstrip antenna capable of achieving a wide bandwidth, a high isolation, low cross-polarisation levels and low backward radiation levels is presented. The H-shaped coupling aperture is used. For wide bandwidth and easy integration with active circuits, it uses the aperture-coupled stacked microstrip square patches. Measured return loss exhibits a bandwidth of over 20.9% and isolation is better than 36 dB over the bandwidth. Cross-polarisation levels and the front-to-back ratio are better than –22 and 21 dB, respectively.