A polar loop transmitter circuit arrangement includes a circuit input, a circuit
output and a controllable signal source. A modulator is coupled between the signal
source and the output, whilst a first logarithmic amplifier is provided having
its input coupled to the circuit input. A second logarithmic amplifier is also
provided having its output coupled to the circuit output. An output of each logarithmic
amplifier is coupled to a respective input of a comparator, and an output of the
comparator is coupled to an input of the modulator. The logarithmic amplifiers
can be successive detection logarithmic amplifiers, such amplifiers having an RF
output which is amplitude limited and can be designed to have constant phase limited output.
