Novel tunnel diode oscillator power combining circuit topology based on synchronisation

Devices with negative differential resistance (NDR) regions in their current-voltage (I-V) characteristics such as tunnel diodes (TD) and resonant tunneling diodes (RTDs) have been used for realizing high frequency oscillators. In this paper, a new power combining technique is presented which combines output power through synchronisation of two coupled tunnel diode oscillators. The measured output power of the two synchronised tunnel diode oscillators realized in microstrip hybrid technology was −6.72 dBm at 716.2 MHz, while that of single tunnel diode oscillator was −9.09 dBm at 575.7 MHz. The circuit topology proposed in this paper can be utilized to realize high power and high frequency RTD terahertz sources.