An Improved Microwave VTO in a to 8 Package

A new miniaturized VTO is described, the aim of the design was a high stability and an improved spectral purity. The high stability is obtained by using a medium power bipolar transistor developed by L.T.T., which operates with a strong current and a low collector emitter voltage. The rejection of the harmonics is provided by a varactor tuned filter controlled by the same voltage as the oscillator varactor. The whole circuit is the result of a computer aided design. An intensive use of lumped R L C elements has allowed a very high density circuit : the whole oscillator is lodged in a TO 8 package. The VTO developed by L.T.T. covers the 600 - 1000, 800 - 1250, 1000 - 1800 MHz frequency range and supplies an output power greater than 20 mW with a harmonic level at least 20 dB lower than the carrier level.