A phase modulator with gain for microwave millimeter-wave systems

A method of achieving phase modulation directly at microwave and millimeter-wave frequencies with concurrent signal amplification is presented. The modulation is achieved with a voltage-controlled oscillator and circulator. The technique is demonstrated experimentally with the generation of a bi-phase coded signal at Ku-band with a signal gain of 10 dB. By cascading multiple VCOs in an injection-locked chain, additional gain and continuous phase variability are possible. A reduction in microwave hardware may be achieved in phase-coding system applications.<>