SDR Advantages For Test Equipment

Abstract - Test equipment manufacturers have begun to implement instrument designs using software defined radio principles and devices. This presentation will provide a brief overview of Software Defined Radio (SDR) techniques, how SDR is implemented in test equipment and the advantages that test equipment manufacturers and customers realize from these designs. Advantages discussed will include:

• Cycle time for initial development
• Extendibility to meet new requirements
• Lower costs
• Faster execution time

INTRODUCTION TO SDR

Software defined radio can be defined as using software or digital electronics to perform the modulation and demodulation functions in a communications system [1]. The goal in developing a system with an SDR approach is to provide a flexible and cost effective system. Features of software defined systems include flexibility across a number of communication standards, and adaptability to new standards as they emerge.

The basic elements of an SDR system include digital to analog (D/A), and analog to digital (A/D) converters and a front end to transmit and receive signals. In the purest sense, there would be no analog frequency conversion in a SDR system, as the D/A and A/D converters would operate at the carrier frequency of the system. With the state of the art of converters, most systems still use at least one analog frequency conversion. Zero IF modulation and demodulation is common in current systems. In zero IF modulators and demodulators convert between the RF carrier frequency and the analog baseband signals.