Microwave oscillator phase noise reduction using negative resistance compensation
Abstract
Two microwave oscillators at a free-running frequency of about 800 MHz are designed. Both were designed to have the same feedback factors; the difference lies in the output loading circuit. By using the inverted common collector configuration, a stable negative resistance is generated. This negative resistance is then used to compensate for the loss in the feedback path. Hence, a zero resistance loaded oscillator is implemented. A comparative study with experimental support confirmed that the zero loaded oscillator has a 6-dB and 18-dBc improvement in the phase noise and second harmonic rejection, respectively.
- Publication:
-
Electronics Letters
- Pub Date:
- February 1993
- DOI:
- 10.1049/el:19930255
- Bibcode:
- 1993ElL....29..379L
- Keywords:
-
- Feedback Control;
- Microwave Oscillators;
- Negative Resistance Devices;
- Noise Reduction;
- Bipolar Transistors;
- Junction Transistors;
- Q Factors;
- Electronics and Electrical Engineering