Carrier less modulator using saw filters

Abstract

A system and method of carrier less modulation is described in this disclosure that uses SAW filters as a modulator in addition to their conventional use as filters for band limiting an UWB system. This system and method is primarily designed to be used with any integer cycle, ultra-wide band or impulse type modulation and more particularly is designed to work with a method of modulation named xMax. This technique exploits the impulse response of the SAW filter producing a carrier less impulse radio system with limited bandwidth, low average power, but high peak power.

Description

DESCRIPTION OF THE DRAWINGS

For a fuller understanding of the nature and objects of the invention, reference should be made to the accompanying drawings, in which:

FIG. 1 is a representation of typical frequency response of a SAW filter;

FIG. 2 is a representation of a Diac Delta Function;

FIG. 3 is a representation of an impulse response of a SAW filter;

FIG. 4 is a block diagram of a modulator.

Claims

1. A modulator used to generate a carrier less impulse modulated Radio Frequency signal from a data source comprising: A Surface Acoustic Wave Filter;an input impedance matching network;said input impedance matching network in electrical communication with a data source and said Surface Acoustic Wave Filter;said input impedance matching network configured such that said input impedance matching network transforms the output impedance of the data source to the input impedance of said Surface Acoustic Wave filter such that a digital signal generated by the data source is supplied to said Surface Acoustic Wave Filter;an output impedance matching network; and,said output impedance matching network in electrical communication with the output of said Surface Acoustic Wave Filter;said output impedance matching network configured such that said output impedance matching network transforms the output impedance of said Surface Acoustic Wave Filter to match other stages of a radio system used to broadcast said carrier less impulse modulated Radio Frequency signal.

2. The modulator of claim 1 wherein said Band Pass Filter is a Surface Acoustic Wave Filter.

3. A method of generating a carrier less impulse modulated Radio Frequency signal comprising: Generating a digital signal using a data source and applying said digital signal to the input of a Surface Acoustic Wave Filter;transforming the impedance of said data source to match the input impedance of said Surface Acoustic Wave Filter such that when the digital signal is applied to said Surface Acoustic Wave Filter a carrier less impulse modulated Radio Frequency signal is generated; and,

4. The method of generating a carrier less impulse modulated Radio Frequency signal of claim 3 wherein said Band Pass Filter is a Surface Acoustic Wave Filter.