Abstract: A data transmission system in which an on/off keyed (OOK) AM/DPSK modulated data signal with an on/off ratio exceeding about 80 dB which has been modulated on a carrier is received at a compact, easily fabricated and battery powered data receiver which operates without automatic gain control and which includes a double loop antenna (diameter of about two inches) with a trimmer capacitor center tapped to the antenna for providing a conjugate impedance match between the antenna and a low noise amplifier. In the receiver, a square-law detection AM demodulator for demodulating the amplified signal is in a bipolar silicon IC, and a DPSK data detector for decoding the demodulated signal is in a separate digital CMOS IC.

Abstract: A broadband, high-gain RF signal amplifier which consumes a minimal amount of DC power has an input terminal to which an input signal to be amplified is coupled, and an output terminal from which an amplified output signal is derived. The signal amplifier has a plurality of first through n.sup.th signal amplification stages coupled in cascade between the input terminal and the output terminal. Each stage comprises an amplifier device having an input electrode, an output electrode and a control electrode. The output electrode is coupled to an amplifier device of an i.sup.th stage that is resistively coupled to the input electrode of the amplifier device of an (i+1).sup.th stage, and is DC coupled through a rectifier device to the control electrode of the amplifier device of the (i+1).sup.th stage. The control electrode of the amplifier device of the i.sup.th stage is resistively coupled to the input electrode of the amplifier device of the (i+1).sup.th stage.