HIGH EFFICIENCY X-BAND SERIES-FED MICROSTRIP ARRAY ANTENNA

A new class of the wideband series-fed microstrip array antenna is presented for X-band applications. A novel configuration of the reflector-slot-strip-foam-inverted patch (RSSIP) is proposed to provide high efficiency and wide operating frequency band. To improve the front to back ratio (FBR) and enhance the gain, a reflector is used. The series-fed configuration is selected for the array to simultaneously provide a very high efficiency and reduce the side lobe level. To experimentally verify the performance, a prototype of the array antenna is fabricated, and measurement is performed. This array consists of 12 sub-linear arrays with series-fed microstrip excitation. Also, each of these subarrays consists of 16 RSSIP antennas. An excellent agreement exists between measurement and simulation. The measured gain and efficiency of the fabricated antenna are 28.5 dB and 67% at 10 GHz, respectively. The measured impedance matching bandwidth (S11 < −10 dB) is 24% which confirms the wideband characteristic of the antenna. The series-fed configuration results in very low measured SLL of −24.5 dB at H-plane. The proposed 16×12 array antenna is a proper candidate for applications in MIMO systems and synthetic aperture radars (SAR).