Noise considerations for a tunnel diode integrated rectangular patch antenna

The tunnel diode integrated rectangular patch antenna is investigated, with emphasis mainly on noise considerations. Noise power is calculated and is found to increase very slightly with frequency for both GaAs and Ge tunnel diode loaded patches. Noise figure and noise temperature also increase with frequency for GaAs and Ge tunnel diode loaded patches. Loading the patch with the tunnel diode increases the effective noise figure and effective noise temperature of the patch, degrading the performance of the communication system significantly.     

Tunnel diode-loaded rectangular microstrip antenna for millimeter range

Theoretical investigations conducted for Ge tunnel diode-integrated rectangular patch antenna reveals that such an antenna exhibits frequency tunability with the bias voltage. The Ge tunnel diode-loaded patch can be operated in the millimeter range (51.042-54.013 GHz). The range of frequency obtainable for operation is 2971 MHz. The radiation pattern shows variation with the bias voltage and the radiated power, the beamwidth and the directivity vary inversely with the bias voltage. Thus, the Ge tunnel diode-loaded patch can be used to achieve electronic tuning (BW=5.66%) with the bias voltage.     

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     

Double U-slot rectangular patch antenna

A rectangular microstrip antenna with two U-shaped slots on the patch is described. Using a foam layer of thickness ~8% wavelength as the supporting substate, an impedance bandwidth of 44% is achieved. The radiation patterns are stable across the passband     

Aperture coupled microstrip patch antenna with thick ground planein millimetre waves

The finite thickness of the ground plane is taken into account in the cavity model to analyse some aperture coupled microstrip patch antennas at millimetre-wave frequencies (60 GHz). The thickness has a strong effect on impedance matching at high frequencies owing to the ratio between the thickness and the wavelength, which increases with frequency. The calculated results are compared to those obtained by experiment for several antennas with different input impedances due to different slot lengths. Close agreement is found between the calculated and experimental results     

Resonant frequency of a tunable rectangular patch antenna

The uniform transmission-line model is applied to determine the resonant frequency of a coaxial probe fed rectangular patch antenna tuned by a number of passive metallic posts suitably placed within the antenna's boundary. An approximate expression is given for the resonant frequency as a function of the post location and number, and of the other characteristic parameters of the antenna. Theoretical results are compared with available measured values.     

Far field radiated by rectangular patch microstrip antenna

Using the volume equivalence theorem, we introduce electric and polarisation current distributions for a rectangular patch microstrip antenna. These distributions are known from transmission-line-model analysis. Literal formulas are given especially to express the E-plane radiation pattern and the worst-case crosspolarisation level. Theoretical results are in good agreement with experiments.     

Long rectangular patch antenna with a single feed

Radiation characteristics of a long rectangular patch antenna excited by a single feed are investigated. The equivalent circuit of the patch including the feed line section is developed. It is found theoretically that a single feed long rectangular patch supports a leaky traveling wave along the length of the patch. The complex propagation constant of the traveling wave is estimated by solving the wave equation with impedance boundary conditions. Radiation patterns of the antenna are obtained using the principle of equivalence. Various radiation characteristics of center-fed and end-fed long patch antennas are presented     

Designing rectangular patch antenna using the neurospectral method

This paper presents a new method for developing computer-aided design (CAD) models, using spectral domain (SD) formulation. Using the artificial neural network (ANN) technique, a combination of continuous function and delta functions constitutes the spectral domain Green's functions. We obtain closed-form formulas for integration involving these equations. Another neural network relates different antenna parameters. Utilizing the reverse modeling for patch dimension determination, it becomes useful as a CAD model for patch antenna design. Designs, of simple rectangular patch antennas, serve as illustration of this method.     

Meshed patch antenna integrated into car windscreen

An investigation into the performance of a microstrip patch antenna integrated into a laminated glass windscreen for a vehicle is presented. It is fed using a coplanar waveguide feed printed on the innermost layer of the glass avoiding the need for a contacting feed. The patch and ground plane are meshed for manufacturing in the glass     

Edge effects for resonance frequency of covered rectangular microstrip patch antenna

Edge effects using the variational method are calculated and included in the resonance frequency calculations of a rectangular patch antenna covered with a dielectric superstrate. These are compared with the reported experimental results and those based on available theoretical expressions. The calculations are found to more closely agree with reported experimental values.<>     

Approximate expression for the resonant frequency of a rectangular patch antenna

An approximate expression is derived for the resonant frequency of a rectangular patch antenna. It shows explicitly the dependence of the resonant frequency on the characteristic parameters of the antenna. Accuracy of the expression is established by comparing the theoretical results with available measured results.     

Effect of curvature on characteristics of rectangular patch antenna

The effect of curvature on the characteristics of a rectangular patch antenna is studied theoretically and experimentally. For the TM01 mode it is found that the resonant frequency is not affected by curvature. However, as curvature increases the pattern broadens, the resonant resistance decreases, the Q-factor is smaller and the bandwidth is larger. Good agreement between theory and experiment is obtained.     

Characteristics of a two-layer electromagnetically coupled rectangular patch antenna

Experimental results on the characteristics of a two-layer electromagnetically coupled rectangular patch antenna are presented. The variations of pattern shape, 3 dB beamwidth and impedance bandwidth with spacing s between the two layers are studied for s between 0 and 0.37?0. A relatively high-gain region is found for s between 0.31?0 and 0.37?0.     

A broad-band U-slot rectangular patch antenna on a microwavesubstrate

A broad-band U-slot rectangular patch antenna printed on a microwave substrate is investigated. The dielectric constant of the substrate is 2.33. The antenna is fed by a coaxial probe. The characteristics of the U-slot patch antenna are analyzed by the finite-difference time-domain (FDTD) method. Experimental results for the input impedance and radiation patterns are obtained and compared with numerical results. The maximum impedance bandwidth achieved is 27%, centered around 3.1 GHz, with good pattern characteristics     

Feed reactance of rectangular microstrip patch antenna with probefeed

The input impedance of a microstrip patch antenna is an important design parameter, which controls the radiated power and impedance bandwidth. In the case of a probe fed patch antenna, the total input impedance consists of the probe reactance in series with the patch impedance. Good models for calculating patch impedance are available, but models for the probe feed appear to consider only the inductive reactance. The authors show that the total feed reactance in fact consists of two components i.e. the inductive reactance of the probe plus the capacitive reactance between the patch and the ground plane. The results show that when both the reactance components are taken into account, the agreement between the calculated and measured results is excellent     

Single-feed triple-frequency rectangular microstrip patch antenna with pairs of spur-lines

A rectangular microstrip patch antenna with triple resonant frequencies is presented. Two pairs of spur-lines are embedded in the non-radiating edges of the patch antenna to excite extra resonant frequencies. The placement of spur-lines is made to achieve good radiation efficiency and impedance matching at all three resonant frequencies. Good agreement between the simulations and measurements is obtained.     

Input impedance of rectangular patch antenna fed by microstrip line

A simple full-wave method for analysing rectangular microstrip antennas is presented. The problem of voltage term calculation is elucidated in the case of the microstripline-fed antenna. A new model for calculating the voltage term is proposed and compared to the other two models taken from the literature.<>     

Analysis of rectangular microstrip patch antenna covered with N-dielectric layers

A generalized spectral Green’s function formulation of N-layer substrate structure is given with three dimension sources, which is a set of closed form formulas. A full-wave analysis model for rectangular microstrip antennas covered with N-dielectric layers has been established by using the above spectral Green’s function. The unknown surface current density on the microstrip patch for such structure is found as a solution of an integral equation. The input VSWR and radiation patterns of the antenna are also obtained. The numerical results have been verified by the experimental results. Partly supported by the Research Item B96(56) of the Ministry of Railways of China     

Compact dualband rectangular microstrip patch antenna for 2.4/5.12-GHz wireless applications

A dual-band antenna is proposed for WLAN and WiMAX frequency bands. Two resonance frequencies are found to be 2.45 and 5.125 GHz and ?10 dB bandwidth of lower and upper resonance frequencies are 4.13 and 8.82 % respectively. It is observed that frequency ratio is more sensitive with the dimensions of L-shaped slot. The frequency ratio of the antenna for a given dimension of L-slot is found to be 2.092 and gain of the antenna is 3.9 dBi for lower resonance whereas 6 dBi at upper resonance. The theoretical results are compared with the reported experimental result as well as simulated results obtained from IE3D simulation software which are in close agreement.