Analysis of corner microstrip fed patch antenna

A new analytical expression for the input impedance of a patch antenna has been obtained based on the Green function approach which includes the effect of the feed current density vector. The feed reactance is inbuilt and the method is numerically very efficient with a minimal computational requirement     

Analysis of elliptical microstrip patch antenna consideringattachment mode

This paper presents an analysis of an elliptical microstrip patch antenna for circular polarization using the method of moments (MOM) in conjunction with the reaction integration method. The attachment mode was used to ensure the continuity and the singularity of the currents in the patch-probe conjunction point. Results showed that an elliptical patch can be used to generate circular polarization with one probe feed and attachment mode should be used to obtain the exact impedance when excited by a probe     

Characteristics of the cylindrical-circular patch antenna

An analysis of a thin cylindrical-circular microstrip patch antenna is presented. Using the cavity model as a base, formulas are obtained for the far-zone electric field and the input impedance of a coax-fed patch. Numerical and graphical results are given to illustrate the effects of curvature on the characteristics of the TM₁₁ mode     

Polarisation-agile active patch antenna

A polarisation-agile active antenna has been constructed and tested. The radiation can be selected to be circularly polarised in either sense, or linearly polarised in the vertical, horizontal or either diagonal plane. The antenna consists of two varactor diode loaded active patches using npn bipolar transistors in the common base configuration as sources, and with the patch axes at right angles to each other. The two oscillators are locked to an external source, and the phase from each patch element is controlled by varying the diode bias voltage. By appropriate combination of the phase relationships, the various polarisations are produced.<>     

Small microstrip patch antenna

A novel small microstrip patch antenna is presented. The probe-fed circular microstrip patch incorporates a single shorting post which significantly reduces the overall size of the antenna. Experimental and theoretical impedance behaviour and radiation characteristics of the modified patch are given. Very good agreement between experiment and theory was achieved     

Broadband microstrip patch antenna

The characteristics of a rectangular microstrip antenna with an L-shaped probe are investigated. A foam layer with a thickness of around 10% of the wavelength is used as the supporting substrate. An impedance bandwidth of 35% and an average gain of 7.5 dBi can be achieved. The radiation pattern is stable across the passband     

Small dual patch antenna

A novel two-layer rectangular patch antenna has been designed and tested. Compared with a basic single layer patch antenna with the same projection area, the resonant frequency is reduced by 39%. The bandwidth is 5%; the cross-polarization level is less than -15 dB     

Super-wideband monopolar patch antenna

A monopolar patch antenna for wideband operation is presented. it has super-wide impedance bandwidth from 0.77 GHz to more than 20 GHz for SWR 2. Conical radiation patterns are observed. also, it has a low profile of 0.087 free space wavelength at the lower cutoff frequency, 0.77 GHz, of this bandwidth. moreover, it possesses high peak gain and average gain of 9.5 and 6.1 dbi, respectively.     

Microstrip patch array antenna

A microstrip array with mutual coupled rectangular patch radiators is described. By the avoidance of a corporate feeding network, advantages in the antenna performance and design are realisable. Experimental results are presented for both linearly and circularly polarised antennas which demonstrate the usefulness of this special antenna configuration.     

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     

Stacked shorted patch antenna

A novel stacked shorted patch antenna is proposed and investigated both theoretically and experimentally. The new antenna has significantly greater bandwidth than a conventional shorted patch and its behaviour is less susceptible to manufacturing errors. The stacked shorted patch is small in size and, thus, is suitable for mobile communication applications     

Switched-beam single patch antenna

A simple and compact switched-beam antenna is presented. The radiation patterns of the antenna were predicted using the finite difference time domain method. Measurement was performed, and the results show good agreement with predictions. Low correlation can be expected from this antenna for diversity reception     

Analysis of W-slot loaded patch antenna for dualband operation

In the present paper W-slot loaded single and two dielectric layers microstrip patch antenna has been analysed using equivalent circuit concept. The antenna shows dual resonance. The resonance frequency of single layer patch is found to be 2.91 GHz and 3.88 GHz which increases for two layers dielectric antenna up to 4.17 GHz and 5.78 GHz respectively. The frequency ratio is found to be 1.33 for single layer patch antenna and 1.38 for two layers patch antenna. In general the frequency ratio is found to depend on slot length, slot width and slot angle. The bandwidth of single layer patch antenna is found to be 1.71% and 1.68% for lower and upper resonance frequency while it increases for two layers up to 5.28% and 2.77%. The theoretical results are compared with the simulated results obtained from IE3D and both are in close agreement.     

Analysis of cross-aperture coupled patch antenna using transmissionline model

A singly-fed, cross-aperture coupled microstrip antenna producing circular polarisation (CP) has been modelled using the transmission line method (TLM). The model provides an efficient technique to predict the input impedance of the structure with good accuracy when compared to measurement results     

Center-fed microstrip patch antenna

A novel feeding scheme for microstrip patch antennas is presented, which consists of a coaxial probe and shorting pin separated by a narrow slot centrally cut at the radiating patch. The impedance and radiation characteristics of a conventional probe-fed microstrip patch antenna and the proposed microstrip patch antenna are experimentally examined and compared. The effects of the slot length on the antenna operation are also discussed.     

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     

New kind of microstrip antenna: the monopolar wire patch antenna

The monopole wire patch antenna is described as a new invention. It is, in fact, a member of a well known family of monopole variants, well known and much used in the aircraft antenna industry. Some of the early development work was done by Seeley in the late 1950s. The antenna had also been developed by Willoughby and was the subject of UK patents     

Analysis of inclined microstrip patch antenna using enhanced FDTD equations

Using the enhanced FDTD equations for diagonal metal edges, a rectangular microstrip patch, inclined to the grid by 45/spl deg/, has been analysed. The enhanced equations give extremely accurate results even with a coarse grid. The accuracy of the first resonance frequency obtained using the enhanced equations was 1.1%, compared to 7.1 and 3.5% using the staircase and split-cell models, respectively.     

Dual-resonance spiral-like shorted patch antenna

A simple dual-resonance printed antenna based on a spiral-like shorted patch configuration with an additional shorting pin to generate the second resonance is presented. The antenna allows for relatively independent control of the two resonant frequencies. The antenna resonance is at 1.55 and 2.5 GHz. The 10 dB return loss bandwidth is greater than 1.4% across each of the resonant frequencies.