A NOVEL DUAL BAND TRANSMITTER USING MICROSTRIP DEFECTED GROUND STRUCTURE

This paper presented a novel dual band transmitter which operates as power amplifier or frequency doubler with the stop band characteristic of defected ground structure (DGS). It works as a power amplifier at 2.4 GHz which satisfies the 802.11b/g wireless LAN standard or performs as an active frequency doubler at 6.8 GHz which depends on the input frequency and. The equivalent circuit and the stop band characteristic of the proposed microstrip DGS are analyzed and simulated. For the proposed transmitter, second harmonic suppression is below −52.6 dBc in the amplifier mode, and fundamental suppression is below −41 dBc in the frequency doubler mode with the stop band characteristic of DGS. The designed transmitter used GaAs InGaP Heterojunction broadband MMIC. It achieves 13.7 dBm of P 1d B and its gain is 16.5 dB in amplifier mode, and its maximum output power is 7.8 dBm at 6.8 GHz in frequency double mode.