An experimental low-voltage I-band oscillator assembled with only five SMD-components

An easy to assemble experimental I-band oscillator which uses only five SMDcomponents is described. The resonant circuit is built up by two microstrip lines and an interdigital capacitor etched on a common FR4 substrate, respectively. Only two junction field-effect transistors (JFETs), two capacitors and one resistor are necessary to build up this low-cost oscillator. With a supply voltage of 3.0 V, an output power of more than 1 mW is achieved at an operating frequency of 9.24 GHz. The measured suppression of the harmonics is better than 55 dBc. The realised oscillator has small geometrical dimensions and is very well suited to be manufactured as a monolithic microwave integrated circuit (MMIC), too. Integrating an additional tuning diode Will enable the oscillator to serve as a low-voltage VCO in a smallband PLL circuit.