Broadband Circular Microstrip Antenna Research Articles

The use of a pair of spur lines for broadband circular microstrip antenna with embedded reactive loading

This communication demonstrates the use of a pair of spur lines for a broadband circular microstrip antenna with an embedded reactive loading. With the use of the spur lines, the impedance bandwidth of the proposed design can be enhanced. The obtained bandwidth can reach up to 112.5 MHz, which is about 1.32 times that (86 MHz) of the original broadband antenna without spur lines. The variations in antenna gain within the impedance bandwidth are also less than 2 dBi. Details of the proposed design are described, and experimental results of the antenna performance are presented and discussed.

A broadband circular microstrip antenna with two open-ring slots

This letter presents a new design of a probe-fed circular microstrip antenna with two open-ring slots for broadband operation. Due to the two embedded open-ring slots in the circular patch, two resonant modes of similar radiation characteristics are found to be excited at frequencies in the vicinity of the fundamental resonant frequency (f11) of a corresponding simple circular microstrip antenna without slots. The two closely excited resonant modes can cause the enhancement of the impedance bandwidth of the proposed circular microstrip antenna, and experimental results show that the obtained bandwidth for the proposed antenna can be greater than two times that of a simple circular microstrip antenna. The proposed antenna design and obtained broadband performance are presented. ©1999 John Wiley & Sons, Inc. Microwave Opt Technol Lett 23: 205–207, 1999.

Microstrip-line-fed broadband circular microstrip antenna with embedded reactive loading

Microstrip-line-fed broadband circular microstrip antenna with embedded reactive loading

Broadband circular microstrip antenna with embeddedreactive loading

A novel broadband design for a circular microstrip antenna with reactive loading integrated within the circular patch is proposed and studied. The reactive loading is provided by a microstrip structure of cascaded microstrip-line sections embedded inside a slot cut in the circular patch. The proposed broadband design has been implemented, and the experimental study shows that an antenna bandwidth /spl sim/3.2 times that of a conventional circular microstrip antenna can be obtained. Details of the proposed design are described, and experimental results of the antenna performance are presented and discussed.

Slot-coupled compact broadband circular microstrip antenna with chip-resistor and chip-capacitor loadings

The characteristics of a slot-coupled circular microstrip antenna with chip-resistor and chip-capacitor loadings are studied. With a chip-resistor loading, a significant decrease in the resonant frequency of the microstrip antenna is achieved, which can result in a large antenna size reduction, and the operating bandwidth is also seen to be significantly enhanced. It is also found that, when a chip capacitor is further loaded on the chip-resistor-loaded patch, a more significant decrease in the resonant frequency of the microstrip antenna can be obtained, with the broadband characteristic very slightly affected. Typical antenna designs and experimental results are presented and discussed. © 1998 John Wiley & Sons, Inc. Microwave Opt Technol Lett 18: 345–349, 1998.

Microstrip-line-fed compact broadband circular microstrip antenna with chip-resistor loading

Direct matching of a reduced-size, broadband circular microstrip antenna with a 50 Ω microstrip-line feed is described. This design is achieved simply by loading a 1 Ω chip resistor near the edge of the circular patch, which significantly reduces the resonant frequency of the microstrip patch, broadens the operating bandwidth, and causes a wide variation in the input impedance along the patch edge. The last behavior makes direct matching of the antenna with a 50 Ω microstrip line possible. Several typical designs are presented. © 1998 John Wiley & Sons, Inc. Microwave Opt Technol Lett 17: 53–55, 1998.