BPSK Burst Modem Transmitter With Digitally-Controlled Output Level
Original Publication Date: 1988-Jan-01
Included in the Prior Art Database: 2005-Feb-14
This article describes an output level control circuit for controlling the output of a binary phase shift keying (BPSK) RF modem transmitter. The circuit includes a ROM, a DAC and a lowpass filter (LPF) network. The circuit produces an output RF signal whose envelope is short and has predictable turn-on and turn-off delays, minimum overshoot and well-controlled rise and fall times. Furthermore, the circuit allows arbitrary granularity in the output level control and a very wide dynamic range. Due to the digital nature of the circuit, no adjustment is necessary, and the output level control is insensitive to temperature, power supply variation and component aging.