A novel QPSK Modulator

QPSK is a modulation scheme used to represent digital data. Any modulation scheme uses finite number of different signals to represent digital data. QPSK uses four different phases to represent data. QPSK (Quadrature Phase Shift Keying) scheme is used in various applications in modern digital communication system; it provides high performance on bandwidth efficiency and bit error rate. The areas include wireless communication, mobile communication and Satellite Communication. Various QPSK Modulators are available already like the ones that are made from counters and MUX, using Balanced Modulators. But these are bulky owing to the use of Transformers for making Balanced Modulators. Our paper shows a novel QPSK Modulator made from OP-AMPS. Use of Op- Amps simplifies the circuit and we can get perfect results. The circuit complexity in terms of size is reduced to a large extent.