A Novel Cross-Slot Geometry to Improve Impedance Bandwidth of Microstrip Antennas

Abstract

Abstract-Circular polarization (CP) designs of circular and rectangular microstrip patch antennas are demonstrated. Proximity coupled feed and aperture coupled feed methods are used. The proposed CP designs are achieved by implementing a suitable crossslot either on the patch (in the case of proximity coupled feed method) or on the ground plane (in the case of aperture coupled feed method), which results in excitation of two near degenerate orthogonal modes of near equal amplitudes and 90 • phase difference. Attempts are made to change the geometry of slots' ends to introduce a novel structure in order to achieve a better matching performance.

A Compact UWB Microstrip Antenna with Modified Ground Plane for Bandwidth Enhancement

“…These two observations imply that the resonant frequency is typically determined by the rectangular microstrip antenna size and slightly detuned by the size of the ground plane. The observation is that, as shown in Figure 2, the first resonant frequency is dependent on the size of the rectangular microstrip antenna as mentioned above while the second resonant frequency and the bandwidth obey the dimension of the cut area at the ground plane corners [20,21]. The rectangular L-slot and diagonal cut are used to improve the impedance matching of the propose antenna to reduce the reflection of surface current, thus adjusting the parameters of slot cut to reduce return loss or enhance the bandwidth of UWB antenna.…”

Composite Compact Triple-Band Microstrip Antennas

“…One of the most effective techniques for improving the bandwidth of compact antennas is chip-resistor loading but at the expense of the antenna efficiency and gain [21][22][23]. Designs of a chip-resistor loaded single-band MSAs fed using a probe or inset microstrip lines have been reported [21,22].…”

A Functional Antenna Tuner for Slot Patch Antenna

“…Since microstrip antenna with wide bandwidth is very important for Wireless-LNA, Bluetooth and Video-interface [4], techniques of modifying bandwidth have been developed a lot. Structurally, it includes integrating several microstrip resonance structures into one antenna [5,6], adding more structural layers to antenna [7], changing dielectric constant of substrate [8,9], modifying probe feed structure [10][11][12][13][14] and printing functional slot to the radiator as well as the ground [15][16][17][18], etc. Lately, by using of stepped [19,20] and slotted ground [21][22][23] for size reduction, parasitic elements for shorting the patch [24][25][26] to modify the bandwidth of microstrip antenna has been reported.…”