DESIGN OF DUPLEXER USING MICROSTRIP FILTERS FOR LOW POWER GSM APPLICATIONS
Keywords:
GSM, duplexer, microstrip filters, matching circuitsAbstract
A duplexer for low power applications is designed using a combination of highpass and lowpass filters that
separates the input signals into two output ports. It isolates the GSM receiver from the high power transmitter by preventing
the addition of unwanted noise on to the receiver noise floor. Duplexer allows both transmitter and receiver to be connected
to a common antenna there by avoiding requirement of two separate antennas (one for Transmitter and another for receiver).
These duplexers can be used in modern cellular repeater amplifiers that rebroadcast cellular signals inside femto cells (that
is, in residential or small business environments). Microstrip technology is used to design the duplexers, which has the
advantage of providing flexibility and device miniaturization when compared with cavity-based designs while still delivering
good performance.