Negative Resistance Circuit (NRC) for HF

[pumanba2]

Hi,

Could anybody recommend me some Negative Resistance Circuits (CMOS) for high frequencies applications?

I'm interested in pure negative resistance independent from frequency for a wide band (several GHz).

I would be very thankful!

(except common cross-coupled mos)

 

[goldsmith]

Could anybody recommend me some Negative Resistance Circuits

Hi
Negative resistance can easily be harvested by oscillators ( positive feedback circuits ) or perhaps via an op amp with some simple additional things .

Best Wishes
Goldsmith

 

[LvW]

Hi
Negative resistance can easily be harvested by oscillators ( positive feedback circuits ) or perhaps via an op amp with some simple additional things .

For "several GHz" ???

 

[FvM]

(except common cross-coupled mos)

Means what? Negative resistance can be implemented by transistors in a wideband positive feedback structure, needs at least two. So cross coupled transistors would be the straightforward way.

By nature of the involved transistors, the negative resistance won't be a pure real impedance, and due to parasitic elements (e.g. bond wires), you can hardly present a negative resistance with GHz bandwidth off-chip.

 

[goldsmith]

For "several GHz" ???

Hi Dear LvW

As i can remember about one or two years ago there was a discussion regarding the same issue here , and i remember FvM answered this as using oscillators i told that idea , based on what i saw in that time . so if i'm wrong you correct me please .

Yours Sincerely
Goldsmith

- - - Updated - - -

you can hardly present a negative resistance with GHz bandwidth off-chip.

Hi Dear FvM

What if a Gali-5 be used as a main amplifier which can be used as a wide band amplifier and then adding a positive feedback path ?

Best Regards
Goldsmith

 

[godfreyl]

Tunnel diodes and Gunn diodes have a negative resistance characteristic and work at microwave frequencies.

Is there any reason you specifically want a CMOS circuit?