Microstrip antennas have been most rapidly developing in the past 20 years. Currently these antennas have a large application in mobile radio systems, integrated antennas, satellite navigation receivers, satellite communications, direct broadcast radio and television, etc. The considerable interest in microstrip antennas is due to their advantages such as light weight, low volume, conformability, and ease of manufacture. One of the most serious disadvantages of microstrip antennas is their limited bandwidth. Most of the research on microstrip antennas has been aimed at overcoming this drawback.

Yun and Yoon [1] presented an aperture-coupled wideband microstrip array antenna using inverted feeding structures. Wideband microstrip arrays using the U-slot antenna element are proposed by Lee et al. and Lau et al. [2,3]. A wide-bandwidth patch antenna fed by an L-shaped probe is presented by Wong and Luk [4]. Early in 1981, Dobust presented a H-shaped slot type antenna [5]. Recently, a tooth-like-slot patch based on the low temperature co-fired ceramic (LTCC) technology was investigated by Wang et al. [7] and the impedance bandwidth of this novel element is about 20% [6, 7].

Several papers have been published in recent times with notch microstrip antenna to achieve dual band characteristics. Palit and Hamadi [8] have reported a microstrip antenna by properly cutting a notch inside the radiating element. This gives enough bandwidth for dual band frequency and wideband operation. This idea of the notch has been incorporated in this study.

The proposed design consists of a two element rectangular microstrip array antenna. We have modified one element by placing the rectangular notch at each edge of the patch, converting it into plus shape [9] to obtain a hybrid array. The elements of the array are fed through simple corporate feed network which results in a wideband of 19.02%. The study is carried out for four elements hybrid array and further it is extended to eight elements which results into multifrequency, covering both C- and X-band with improvement in impedance bandwidth to 31.06%.

Science and Technology Journal, Microstrip Array Antenna, Half Power Beam Width (Hpbw), Satellite Communications, Direct Broadcast Radio And Television, Mobile Radio Systems, Antenna Geometry, Synthetic-Aperture Radar (Sar), Dth Applications, Department Of Science And Technology (Dst),Vector Network Analyzer.