Frequency Modulation of a Millimeter-wave IMPATT Diode Oscillator and Related Harmonic Generation Effects

Abstract

In this paper we report the performance of a continuous wave millimeter‐wave IMPATT diode oscillator with a wide‐band tunability. The diode is mounted in an iris wafer circuit; its oscillation frequency can be modulated either by a varactor diode or by direct modulation of the IMPATT diode bias current. The oscillator has been successfully used as a millimeter‐wave frequency deviator in an experimental pulse code modulation millimeter‐wave system. We also report detailed measurements on subharmonic frequencies in IMPATT diode oscillators. Experimental results show that wide frequency tunability can be obtained with a circuit which provides an “idler” resonance at one‐half the fundamental transit‐time frequency. The results also show that by providing “idler” resonances at both the transit‐time frequency and at one‐half of the transit‐time, the oscillation at 3/2 the transit‐time frequency is enhanced and yields a useful output power of 2 mW at 86 GHz.

Si/Ge Avalanche Photodiodes-Based Electrical Comb-Line Generators and Photoreceivers for Very-Fast Impulse Radio Wireless Linking

“…The resonant frequency of the Si/Ge APD used in this letter is at around 5 GHz [7], which is slightly increased with an increase in reverse bias voltage [7]- [10]. In order to generate frequency comb-lines, we must inject the electrical IF signal into our device under resonant operation in order to "deviate" from the original oscillation frequency [12]. Due to the strong device nonlinearity during oscillation, a large number of frequency comb lines with the spacing equal to the injected IF frequency, as will be discussed latter.…”