Based On The Research Of S-band Microstrip Antenna And Design

With the rapid progress in the wireless communication technology developing, the microstrip antenna, as a vital part in the RF and microwave circuits for the reception and launch, has become an important subject for researching. This paper studies and designs several of the microstrip antennas in the S-band, and discusses the theory of the meander line, and its effect on antennas’ miniaturization.This paper describes three types of microstrip antennas which working in S-band, the printed whip antenna, the inverted-F antenna, and the loop antenna. In this paper, the effect on antennas’ characteristic and minimizing their size by loading the mender lines were discussed, and the comparative analysis of the same antenna with or without this structure was given.The discussion about the meander line is the central part of this paper. Loading the meander lines plays a favorable effect on the reduction of antennas’ size, and brings a little impact on the effective bandwidth and the antenna characteristics. The size of the printed whip antenna with meander lines is reduced by15%comparing with the printed whip antenna. This structure also plays a similar role when utilizing it in the inverted-F antenna and the antenna’s horizontal length is reduced by about25%. The loop antennas have symmetrical structure, the areas of PCB occupied by the antennas are reasonable (121-256mm2).The area of the square loop antenna with three meander lines structure (121mm2) slightly larger than the compact inverted-F antenna’s (111.36mm2). Loading the meander lines makes the effective bandwidth ofthe antennas drop, but adjusting antennas’ structure will make up for their reducing.Through the simulation and design, the following were noticed. The loop antennas have the widest effective bandwidth; the whip antennas take the middle place, followed by the inverted-F antennas. The effective bandwidth of the square loop antenna with the meander lines is about900MHz, and the inverted F antenna is only92MHz. Although the loop antennas’ size slightly larger than the inverted-F antennas’, the loop antennas’ input impedance are stable when the frequency changes in the application’s band, so the effective bandwidth is relatively wide, leaving a margin for the fabrication. There were simulations and measurements for these microstrip antennas that mentioned above. Finally, the trial antennas were taken the input voltage standing wave ratio test and the practical application of the received signal power strength test and the results validated the correctness of the simulation analysis, the cause of deviations was discussed.