SAW Pulse Compression
Product Search
What We Need to Know
Alt Text Here

Before the radar system designer can completely define the pulse compression subsystem, it is necessary to specify the fundamental parameters dictated by the system requirement, these are:

Receiver Resolution

This includes the 3dB width and the sidelobe level of the compressed pulse and hence is the parameter which determines the required bandwidth for the system.

Transmit Pulse Length

Determined by the system range requirement and available peak transmitter power.

Doppler Shift

Determined by the radar RF frequency and relative target velocity.

Mismatch Loss

There is an inherent mismatch loss associated with linear-FM pulse compression techniques caused by the use of a weighting function in the compression filter to reduce time sidelobes. Values of between 1dB and 1.5dB loss are typical. This can be reduced to ~0.1dB through use of matched non-linear FM coding at the expense of increased sensitivity to Doppler shifted frequencies. COM DEV International has a comprehensive range of linear and non-linear designs and can provide hybrid non-linear versions which provide a design trade-off between low mismatch loss and Doppler sensitivity.

From a knowledge of these parameters, COM DEV International may be able to offer a number of standard subsystem designs which are close to your requirement. When you have finally settled on the specification you require, we will offer help on trade-offs, interfacing, MTBFs, mechanical aspects (together with a host of other details) and will complete a full subsystem specification or Statement of Compliance, as appropriate. Either way, you can be assured of the best balance of performance parameters for your system.

Subsystem Configuration

In its simplest form, a pulse compression subsystem comprises:

  • Transmitter (Expander) section which houses one SAW device* with its associated electronics to generate a transmit waveform.
  • Receiver (Compressor) section which houses one complementary SAW device with its associated electronics to produce a compressed pulse from the transmitted waveform.

These two sections can be combined into one box or two separate boxes for maximum flexibility. Some radar systems require complex configurations combining a number of expander and/or compressor devices.

COM DEV International supplies subsystems which include:

  • Multiple pulse lengths for switched range and resolution.
  • Multiple matched compressor channels for use in tracking or sidelobe cancellation applications.
  • Coherent operation with pulse-to-pulse phase jitter less than 0.1° rms
  • Low sidelobe levels 

COM DEV International will be pleased to discuss capabilities and requirements with customers who have a need of these or other specialised requirements. 


For an entirely new system design there is a need to explore the optimum parameters and the effects of errors. Our experts will advise and supply simulations if required.

 

COM DEV International, Lochend Industrial Estate, Newbridge, Edinburgh, EH28 8PL, Scotland
Tel: 0131 333 2000 | Fax: 0131 333 3607 | COM DEV Europe Limited Registered England and Wales Company Number: 1863723