Radiation characteristics of switchable ferrite microstrip array antenna

Radiation characteristics of a switchable microstrip planar array of circul ar patch antennas printed on ferrite substrate with a normal magnetic bias field are described. The extra degree-of-freedom offered by the biased ferr ite can be used to obtain a number of novel characteristics including switc hable and tunable radiations from a microstrip antenna with a single feed p oint. In such a case for antenna radiation, most of the power will be conve rted into magnetostatic waves and little radiates into the air. Under such circumstances the antennas are off, in the sense that they are effectively absent as radiators. Properties of a switchable antenna in an S band (3GHz) are investigated.