By Topic

Design & Analysis of an X-Band QPSK Modulator using Direct Carrier Modulation Technique

Sign In

Cookies must be enabled to login.After enabling cookies , please use refresh or reload or ctrl+f5 on the browser for the login options.

Formats Non-Member Member
$33 $13
Learn how you can qualify for the best price for this item!
Become an IEEE Member or Subscribe to
IEEE Xplore for exclusive pricing!
close button

puzzle piece

IEEE membership options for an individual and IEEE Xplore subscriptions for an organization offer the most affordable access to essential journal articles, conference papers, standards, eBooks, and eLearning courses.

Learn more about:

IEEE membership

IEEE Xplore subscriptions

1 Author(s)
Maria Siddiqua ; RF/Microwave Communication System Laboratory, SUPARCO. mariasiddiqua@yahoo.com

This paper presents the design and simulation of a QPSK modulator (quadrature phase shift keying) based on direct carrier modulation technique with a very simple circuitry. In this design, two double balanced mixers; branch-line coupler and Wilkinson power combiner are used. The selection of a double balanced mixer, being the main component of the design, is a critical issue. Specifications of mixer such as conversion loss, interport isolation etc are discussed. Branch-line coupler is used to produce in phase and quadrature signals and Wilkinson power combiner is used to combine the two modulated orthogonal signals at the output. These passive components are easy to fabricate, occupy reasonable area and provide satisfactory performance as compared to their counterparts. The simulated spectrum and static constellation diagrams of the modulator are presented. The circuit has been designed at 8.3 GHz X Band for 150Mbps bit rate.

Published in:

2006 IEEE International Multitopic Conference

Date of Conference:

23-24 Dec. 2006