1MHz to 10MHz Electronic Controlled ILO
Description:
This project is part of a hardware designed and realizated for my thesis and is part of an useful instrumention suitable to study the problem of shifting-bias in the ILO (Injection Locking Oscillator) by a RF bench.
The core of the circuit, as showed above, is a grounded-gate Colpitts in which the operator can choose, by appling controlling 0|5V-DC signals, between voltage/current/hybrid polarizzation network and between Hi/Low-Q.
Another feature implemented is the possibilty to inibit the oscillation by an inibit-control mechanism (another JFET that pull down the load of oscillator).
As you can note the current polarizzation network is a variant of classical current pump. For biasing this ILO three voltage-source are needed, obviously approriate fixed bias network (not implemented), instead three variable voltage sources, can be used (for general purpose).
There are also the one gamma-LC-filter for decouplig the digital multimeter used for make DC measurments and three pi-greco-LC-filters for decoupling programmable voltage source (Digital SMU in my case). All switch-mechanisms are implemented by reed-reley.
The same project is useful as when the white-box approach is used (therefore the software can control the circuits by knowledge of component parameter and other calcolus procedures) as with black-box measurment's purpose. Ending the frequency of this realization is 1MHz but the same project was exended until 11.7MHz (is sufficient change the Q-factor & free-running oscillation frequency).
Realization:
