[time-nuts] Varactor frequency dividers question

[cdelect at juno.com]

Hi,

I'm looking for a copy of the following document.

"Parametric frequency divider basics. (technical note )"

>From the Microwave Journal Sept 1 1989.

Can anyone help?

Thanks,

Corby

Abstract below.

>>>Since the introduction of half octave bandwidth microwave frequency
dividers and full octave models, parametric frequency dividers have found
applications in many microwave systems. 
General Description 
The parametric frequency divider is constructed using two varactor diodes
in a resonant circuit. These diodes are biased slightly forward under
normal operation. The input signal capacitively is coupled into the
matching network for the two diodes, where it drives both of the diodes
in phase. Due to the modulation of the varactor's capacitance at the
input frequency f, a subharmonic resonance is set up in the diode pair at
half of the input frequency, f/2. [1] This signal appears across both of
the varactor diodes, but at 180[degrees] out of phase with each other. It
is possibly, by using a balun connected to both diodes, to cancel the
input signal f. However, by observing the signal on one of the diodes in
the time domain, it can be seen that balancing is unnecessary. This
signal appears as a negative impulse train with a period of f/2, with a
positive maximum at the varactor's turn-on threshold voltage of 0.7 V. An
electrical schematic diagram of a typical divider is shown in Figure 1. 

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