Switched Antenna Circuit With Increased Information Bandwidth

An
L
-band microstrip patch antenna is directly modulated with fast-switching p-i-n diodes over a range of modulation frequencies well beyond the resonant bandwidth of the antenna. The experimental results, in both the time and frequency domains, show that by using this direct modulation technique, a narrowband patch antenna with a -10 -dB reflection coefficient bandwidth of 28 MHz successfully transmits a directly modulated signal with a bandwidth greater than 300 MHz.