Analysis of notch-loaded patch for dual-band operation

435-442Analysis of notch loaded rectangular patch antenna for dual-band operation has been proposed, in which dual frequency behaviour is obtained by notch loading. The theoretical analysis is based on modal expansion cavity model. The resonance frequency changes with the variation in the length and width of the notch. Thus the input impedance, VSWR, return loss and bandwidth are calculated. The obtained resonance frequency ratio is variable from 1.17 to 1.77 with the length and width of the notch

Tunnel diode integrated two-layer microstrip patch antenna

349-356Theoretical investigations were carried out on the GaAs and Ge tunnel-diode- loaded patch with one parasitic element. It has been found that the radiated power increases due to mutual coupling between the patches typically by 1.95 dB in case of GaAs tunnel-diode-loaded patch and 5.95 dB in case of Ge tunnel-diode-loaded patch. It is also observed that the antenna can be operated over a range of frequency from 0.9975 GHz to 1.0002 GHz for GaAs tunnel-diode- loaded patch and from 56.694 GHz to 64.729 GHz for Ge tunnel-diode-loaded patch just by varying the bias voltage

Triangular microstrip stacked antenna for dual band operation

205-208Experimental investigations conducted on triangular microstrip stacked antenna (TMSSA) to achieve dual band operation by optimizing the number of elements reveal that TMSSA attains the maximum -10 dB return-loss band of 688.6 MHz for (1+3) structure for second resonance. The air gap spacing of 2.5 mm in (1+1) structure improved -10 dB return-loss (RL) band by 612.14 MHz as compared to 242.3 MHz for zero spacing in first resonance (frl). It is also observed that -10 dB return-loss band depends heavily on the angular rotation (non-alignment) in the (1+1) structure

Noise considerations in Gunn integrated rectangular microstrip antenna

148-154In the present paper, noise behaviour of the active patch antenna (GaAs Gunn integrated patch and InP Gunn integrated patch) has been theoretically investigated and consequently the noise figure, noise temperature and noise power are calculated as a function of bias voltage. The noise performance of InP Gunn integrated patch is found to be much better than that of the GaAs Gunn integrated patch

IMPATT integrated active microstrip antenna

357-362An IMPATT diode integrated rectangular patch is theoretically investigated based on the circuit concept in the millimetre range. The various parameters or the antenna are found to depend on the bias voltage and there is marked improvement in the tuning range, radiated power and bandwidth. The antenna exhibits bandwidths of 20% for 1.5:1 VSWR and 35% for 2:1 VSWR. The antenna shows frequency agility for a band of 614 MHz, i.e. 1.7837 % band

Gunn integrated microstrip active antenna

40-44Investigations conducted on an active microstrip antenna (Gunn integrated with microstrip patch) in X-band show a marked improvement in the tuning range, beam width, gain and bandwidth. Theoretically predicted tuning range is 12% as compared to 9% of the reported data. The theoretical results are I good agreement with the reported experimental data

Theoretical analysis of linear array antenna of stacked patches

125-130A linear four-element stacked array antenna is analyzed. It is observed that stacked element array antenna shows marked improvement in the bandwidth and gain over the single-element array antenna. The bandwidth of the stacked antenna array improves to 14.8% over the 4% bandwidth of the single-element array antenna, whereas the radiated power is enhanced by 0.82 dB as compared to the single-element array antenna. It is further observed that the resonance frequency, gain and directivity are highly dependent on the thickness and permittivity of the upper substrate

Shorting pin loaded microstrip antenna for dual-band operation

281-284The series and shunt inductivity introduced by the probe and shorting pin respectively, in a single-feed shorted rectangular microstrip antenna has been evaluated theoretically using transmission line method. The proposed structure provides compact dual band operation using single feed mechanism. The input impedance, VSWR, is calculated theoretically. It is found that the ratio of the resonant frequencies highly depends on the position of shorting pin

Electronic scanning in linear active antenna array

357-362The beam scanning characteristics of 1×4 linear Gunn-integrated active antenna array are investigated by varying the bias voltages of the different elements in the array keeping the side lobe level at least 10 dB down the main beam level. The optimization of beam scanning by varying the bias voltage of all the four elements simultaneously exhibited a beam scanning of 40° with power deviation of 1.85 dB in main beam, which is better than the earlier reported data