A switch IC implemented by four depletion-mode field effect transistors for dual-band GSM switch diplexer module

A new switch design method by applying depletion-mode field effect transistor for dual-band GSM switch diplexer module is presented here. If compared with switch module implemented by using PIN diode, the new module would not only save more currents, consuming only around 0.4 mA in transmitting mode, but also match totally in terms of logic control function and pin-to-pin replacement. If compared with other switch modules also by using depletion-mode field effect transistor, the new module needs only four transistors instead of eight transistors and excluding the use of any voltage supply.