Wideband and high-gain one-patch microstrip antenna coupled withH-shaped aperture

The design, fabrication, and experimental implementation of the one-patch microstrip antenna coupled with an H-shaped aperture are presented. The presented antenna has a wide bandwidth, high gain, and low cross-polarisation levels with only one-patch. The measured bandwidth of this antenna is 56.2% for the voltage standing wave ratio ⩽2.0. The cross-polarisation level is below -18.2 dB at the E-plane and below -25.7 dB at the H-plane. The maximum gain at 2.05 GHz is 10.4 dBi and the 3 dB gain bandwidth with a centre frequency at 2.17 GHz is 24%     

Wideband stacked patch antenna fed by meandering probe

A meandering probe fed stacked patch antenna is presented. The stacked patch configuration can greatly enhance the impedance bandwidth. Bandwidth of up to 37% (SWR<1.5) has been achieved. The cross-polarisation is less than -20 dB across the operating bandwidth. The proposed antenna has symmetric co-polar radiation patterns in both E- and H-plane. The antenna has a gain of 9 dBi.     

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     

Dual-polarised dielectric resonator antenna with high isolation and low cross-polarisation

A novel, dual-polarised dielectric resonator antenna with high-isolation and low cross-polarisation is presented using a hybrid feeding technique. Port isolation of 35.9 dB and a cross-polarisation level of 234 dB are measured. The impedance bandwidth of return loss less than 210 dB is 440 MHz (7.9%) with a centre frequency of 5.7 GHz. Since its feeding mechanism is symmetric, a symmetric radiation pattern is also achieved. It is suitable for the application of synthesis aperture radar and some wireless systems.     

Wideband patch antenna with low cross-polarisation

A wideband patch antenna with low cross-polarisation is presented. Based on a novel meandering-shaped probe feed, an impedance bandwidth (SWR<2) of 24% has been obtained. The cross-polarisation is less than -20 dB across the operating bandwidth. The antenna has a gain of 9dBi.     

Proximity-coupled stacked circular-disc microstrip antenna withslots

The design and measured results of a proximity-fed stacked circular-disc antenna are described. The antenna has an impedance bandwidth of 26%, centred around 4.2 GHz, a gain of 8 dBi, and -30 dB cross-polarisation. An essential feature of the design is the presence of four linear slots in the bottom patch of the stacked arrangement     

Beam steerable square loop antenna over hybrid high impedance surface

A novel hybrid high impedance surface is presented and a beam steerable four feed square loop antenna is built on this structure. At a test frequency of 4.7 GHz, the proposed hybrid high impedance surface based square loop antenna is 4.69 mm high and has an impedance bandwidth of 650 MHz and directivity of 8.7 dBi. Compared with the earlier reported steerable square loop antenna the new antenna s performance equates to a thickness reduction of 61, bandwidth enhancement of 150 , a directivity improvement of 2 dBi, a co-polar sidelobe reduction of 11 dB, and a cross-polarisation sidelobe reduction of 5 dB.     

Coplanar waveguide fed wideband slot antenna

A new design for a coplanar waveguide (CPW) fed slot antenna is presented. The impedance matching and the radiation characteristics of this structure were studied using the method of moment technique. This antenna has an impedance bandwidth (for a VSWR<2) of 49% and a radiation bandwidth of 42% about its 4.8 GHz centre frequency, compared to the 12-20% impedance bandwidth of the standard CPW fed slot antenna. The cross-polarisation in both the principle planes is at least 20 dB below co-polarisation across the entire bandwidth. Simulated and measured results of the antenna are presented. This wideband antenna has significant applications in wireless technologies     

Small rectangular patch antenna

A novel folded rectangular patch antenna is designed and measured. Compared with a conventional patch antenna with the same surface area, the resonant frequency is reduced by 37%. The cross-polarisation level is ~-20 dB     

Microstrip-fed quasi-Yagi antenna with broadband characteristics

A compact and uniplanar antenna with broadband characteristics is presented. The novel Yagi-like printed dipole array antenna is fed by a microstrip-to-coplanar strip transition, and uses the truncated microstrip ground plane as its reflecting element. An X-band prototype measures a bandwidth of 17%. With 6.5 dB gain, 18 dB front-to-back ratio, and lower than -15 dB cross-polarisation level at 10 GHz     

Honeycomb wire antenna

A honeycomb wire antenna is numerically analysed. The radiation in the direction normal to the antenna plane is linearly polarised with a low cross-polarisation component of <-30 dB. The gain is dependent on the interior angles of the radiation cell. The maximum gain for a honey comb antenna of two cells by 17 cells with interior angles of 70° is ~20.5 dB, and the gain drop over a 4% frequency bandwidth is ~2.56 dB     

Linearly polarised radial stub fed high performance wideband slotantenna

A wideband printed slot antenna fed by a radial stub operating over the mobile communication bands PCN (1.716-1.880 GHz) and UMTS (1.9-2.0 GHz and 2.1-2.2 GHz) is presented. The impedance bandwidth of the antenna achieved for a VSMR⩽2 is 34% and the radiation patterns remain stable over the entire frequency band of operation (1.7-2.4 GHz) with cross-polarisation levels of less than -20 dB. Simulated and measured radiation pattern and return loss results are presented     

Proximity-coupled U-slot patch antenna

The design and experimental results of a proximity-coupled U-slot microstrip antenna are presented. The impedance bandwidth (VSWR⩽2) of the antenna is 20%, centred at 4.3 GHz. It has an average gain of 7.5 dBi and a cross-polarisation of about -20 dB. Both gain and radiation patterns were measured across the passband. An essential feature in the design is that a Π-shaped feed line is connected at the end of the usual microstrip line     

Measurement and analysis of miniature multilayer patch antenna

Although the microstrip patch antenna has a number of advantages such as low-cost and light weight, its physical size is quite large at low microwave frequencies. The designs of multilayer miniature patch antennas with coaxial feed are presented. The first design is a rectangular two-layer patch antenna. Measured results and the results of a preliminary analysis are presented. The projection area of the two-layer patch antenna is kept the same as the single-layer rectangular patch antenna. The resonant frequency of the two-layer antenna is reduced by 50% and has bandwidth of 5%, which is wider than the single-layer rectangular patch antenna. In the second design, the upper patch is cut into a bow-tie shape. This results in a 60% reduction in resonant frequency and a 12% bandwidth. Both the two-layer rectangular and the two-layer bow-tie antennas have good radiation patterns, with cross-polarization level lower than the copolarization level by more than 20 dB     

Dual polarised multibeam antenna

A dual polarised four-beam antenna array for the 1850-1990 MHz frequency band is presented. The polarisations are ±45° to vertical. The antenna has eight inputs corresponding to two orthogonal polarisations and four beams. The return loss and cross-polar isolation for a single Butler beam exceeds 15 and 22 dB, respectively. The radiation pattern is similar to an ideal Butler pattern and the cross-polarisation level is <-21 dB in the beams     

Broadband patch antenna with ring slot coupling

A novel broadband linearly polarised patch antenna design is achieved using an H-shaped patch coupled to a microstrip feed line via a ring slot in the ground plane. The results indicate that a wide impedance bandwidth of 54% (2.3-3.845 GHz) can be achieved, together with a broadband gain of 6.6 dB and low levels of cross-polarisation.     

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     

Coplanar waveguide fed quasi-Yagi antenna

A novel coplanar waveguide fed quasi-Yagi antenna is presented. A wide bandwidth is achieved by using a broadband coplanar waveguide to a slotline balun. An X-band prototype has been realised which demonstrates a broad bandwidth (30%), -19 dB front-to-back ratio, and cross-polarisation better than -17 dB at 10 GHz.     

Low-cost X-polarised broadband PCS antenna with lowcross-polarisation level

A broadband personal communication system (PCS) antenna concept, based on a low cost stacked patch approach is presented. The manufactured single element shows an insertion loss bandwidth (-14 dB) of 15.9% and is dedicated to the established PCS 1800 system including the DECT frequencies. The base station array antenna, a 1×8 element column array, is fabricated using dual ±45° polarised single elements. Within the 13.9% bandwidth of the array (-14 dB) the measured level of cross-polarisation is below -16.5 dB over all angles in both principal planes     

ALPSS: a millimetre-wave aperture-coupled patch antenna on asubstrate lens

The feasibility of millimetre-wave (MM-wave) aperture-coupled patch antennas, printed at the back surface of substrate-lenses is demonstrated and the corresponding radiation characteristics are investigated. A specific realisation of such an air-lens-patch-slot-strip (ALPSS) antenna on a low-permittivity ϵ _r=4.0 extended hemispherical lens substrate is theoretically and experimentally characterised at 70 GHz. It is demonstrated that the ALPSS antenna exhibits clean, axially symmetric patterns of low cross-polarisation (26 dB), a directivity of 30.4 dB and the 3 dB pattern full-beamwidth remains within 6°-5° between 60-80 GHz. In addition, a very-high front-to-back (F/B) ratio, of the order of 50 dB is measured at 70 GHz, despite the absence of a backing ground-plane. The ALPSS antenna is well suited for low-cost broadband point-to-point communications and collision avoidance applications