Cellular received signal strength indicator circuit

One very important function of the voice radio at a cell site of a cellular radio system is the identification of the signal strength received at the cell site from various mobile radios. These signal level measurements are used to determine cell assignments during the call origination process and also to determine hand-off of calls between cells. As a result, the strength of these incoming signals must be measured to a fairly high degree of accuracy and over a wide dynamic range. Preliminary results are presented on a device which meets these requirements. The device is highly integrated and makes use of log amplifiers technology to produce an output signal whose voltage level is proportional to the logarithm of the received signal strength. The device is designed to operate at an IF frequency of 10.7 MHz and the design will be briefly described (including necessary filtering interfaces) and preliminary performance results will be presented.