Diode amplifier
Conceived and designed by sv3ora

26-Feb-2021

My previous experiment with the Saturable Inductor Amplifier, gave me another idea. Why not use a diode in place of the inductor and shunt RF to ground using this diode? Thus, my Diode Amplifier was born.

My Diode Amplifier, is based on the principle of diodes used as switches. In this page, I am going to perform a number of practical experiments, to show how my Diode Amplifier can be used to perform different functions in electronics. In this page, I am going to experiment with it in different circuits.

Inverter logic gate

The easiest way to explain the operation of my Diode Amplifier, is by looking at the circuit diagram above. The diagram shows an inverter gate I have built and tested, which works in the following way. When "dcin" is disconnected or tied to ground (logic 0), the "rfosc" RF signal passes through the right diode, it is rectified and it charges the output shunt capacitor, to create a voltage on "dcout" (logic 1). At the same time, the RF signal passes to the left side through the middle capacitor and the negative portion of the signal, is clipped to groung from the middle reverse diode and the reverse diode at the input of the gate. The positive portion of the RF signal cannot escape through the left series diode. The only way this positive portion can escape to the ground, is through the lots of series diodes to the ground. To avoid clipping of the usable positive RF signal, we put more series diodes.
So, a logic 0 at the input of the inverter gate, results in a logic 1 at it's output.

If DC is applied to the "dcin" (logic 1), it is filtered from any RF by the left capacitor and it passes through the series diode, to the middle shunt diodes, where it drives the lots of series diodes into conduction, opening a path for the positive RF signal
out of the "rfosc" to flow to the ground. With most RF signal flowing to the ground, there is little or any signal left to pass to the right voltage rectifier. The right capacitor is then discharged through the load connected to the "dcout" and reaches logic 0. Hence a logic 1 at the input of the inverter gate, results in a logic 0 at it's output.

Comparing my Diode Amplifier to my Saturable Inductor Amplifier, in the Saturable Inductor Amplifier there is no such thing as clipping, but in the diode Amplifier, we have to put more series diodes to avoid clipping. I do not know if this is a disadvantage or not, as one can set the gate gain by adjusting the number of series diodes accordingly. The good thing about this Diode Amplifier is that it can operate even at very low AC frequencies (even mains AC!) in contrast to my Saturable Reactor Amplifier, so this can be made purely with passive circuicity including the AC signal.

To be continued, be patient please...

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