916/926MHz Carrier-Indicator Device
This is a hand held device dedicated to indicate the radio traffic on 916MHz and 926MHz and also the strength of the carrier signal.
The device has the followings main parts:
– The common RF wide band preamplifier – to adapt the antenna input and to perform the amplification of the radio signals;
– The 916MHz and 926MHz splitter – intended to make the RF adaptation between the output of the RF preamplifier and the inputs of two RF receivers of the next stage;
– Two separate Receivers on 916MHz and 926MHz;
– Two separate Differential Amplifiers – in order to extract the carrier signal amplitude for each radio path (916MHz and 926Mhz);
– The Multiplexer – in order to switch the two carriers signals to the same “peak detector” module;
– The Peak Detector module – follows the maximum level of each carrier signal on separate time cycles;
– The Processor (“PIC16C71” ) – has an Analog Digital Converter included who measure the carrier peak level on each frequency (916MHz and 926MHz), verify the battery level and display to an dedicated “Bar Graph LED” the strength of each carrier signals.