Wide Band Image Recovery Mixer.
Final rept. Oct 72-Mar 74,
LNR COMMUNICATIONS INC HAUPPAUGE N Y
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The program was aimed at achieving broadband low noise superheterodyne receiver front ends, without the expense and complexity of using low noise preamplifiers at the signal frequency. The approach was based on recovery of mixer generated image power to obtain reduced mixer conversion loss. A mathematical model for analyzing the image recovery mixer was derived, using scattering parameters and signal flow graph techniques. Based on the analysis, experimental model X-band mixers with I.F. preamplifiers were constructed in both strip line and microstrip circuitry. A noise figure ranging between 4.1 and 4.8 db was achieved over nearly 1 GHz of band width. This represents a one to two db improvement over X-band tunnel diode amplifiers. In addition to offering improved sensitivity, the image recovery mixer-preamplifier provides improved dynamic range and lower cost as compared to a tunnel diode amplifier.
- Electrical and Electronic Equipment