IoT enabled communication device with mixer less low complex QPSK based transmitter architecture for low frequency applications

Technological development in the area of wireless communications lead to the requirement of tight integration of both the digital and analog functional units. Integrating mixers is a challenging task, especially in mixed signal design. IoT communication devices require low design complexity as we expect millions of devices connected. In this paper we propose a mixer less low complex QPSK based transmitter architecture targeting low frequency applications which reduced the complexity in transmitter design. A prototype has been developed using Bipolar Junction Transistors (BJTs) and FPGA as the base band controller. The design can easily be adapted to MOSFET technology and modulation is achieved without the need of generating the carrier externally. The prototype developed was tested successfully by generating frequencies of range varying from 1 KHz to 120 MHz. The proposed architecture can also be used for any other digital modulation scheme such as BPSK, FSK etc.