Abstract-A new reconfigurable microstrip patch antenna allowing switching between two circular polarizations is proposed. It consists of a square radiating patch and a 3 dB hybrid coupler. Using only a single-polar-double-throw (SPDT) switch, the polarization switching can be achieved. This design of the dc-bias network is extremely simple. From experimental results, the proposed antenna avoids the frequency offset phenomena which often happened to antennas with switchable polarization.

In this paper, a wire ring self-structuring antenna capable of altering their electrical shape in response to (SSA) with 23 controllable switches is designed and their electromagnetic environment by controlling the experimented. The controllable switches are chosen PHEMT states of the controllable switches.GaAs IC SPDT Switch AS179-92 of the company In this paper, the template of the proposed antenna is SKYWORKS and are controlled by Single Chip. In order to constructed from 9 rectangles asymmetrically located, reduce the number of control lines, the Hex inverter 74HC04 is t used. The measure results show that the proposed antenna has a the dimension of the rectangles are integral multiples of VSWR bandwidth of 40MHz to 450MHz with VSWR less than dx=7cm and dy=5.2cm. The outer dimensions of the 1.6. template are lx=35cm and ly=26cm. The length of the KeywordsSelf-Structuring Antenna, AS179-92 SPDT switches is lcm, and the wire segments whose width is Switch, Single Chip, Hex inverter 74HC04. 5mm are connected by controllable switches. There are 23 controllable switches in the proposed antenna 1. Introduction template, and the positions and the serial number of these switches are shown in Fig. 1. A photograph of the With the development of wireless technology, various proposed antenna prototype is shown in Fig. 2. communication systems are multi-band, wideband and compact in size. For the capacity of communication

In this article, a wideband wire ring self‐structuring antenna (SSA) with 23 controllable switches is analyzed and designed. The proposed antenna is optimized by the optimal algorithm of genetic algorithm (GA) combined with method of moment (MOM). The VSWR bandwidth of 40–450 MHz less than 1.6 has been achieved by selecting the switches open or closed. Experiments have been carried out with good agreement with simulated results. From the results of measurement, it can be seen that in some combination of switches states, the proposed antenna has wideband performance. © 2009 Wiley Periodicals, Inc. Microwave Opt Technol Lett 51: 817–819, 2009; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.24162