Independently Amplify Voltage or Current at 2GHz

Help: Independently Amplify Voltage or Current at 2GHz ?

Hi all,

Recently I met an interesting question for RF amplifier design. In the design, at a frequency of about 2 GHz (e.g. 2.4 GHz), we want to design an amplifier which can independently amplify "current" or independently amplify "voltage". In the RF power amplifier design, the voltage and current are amplified at the same time.

As we know, today Operational Amplifiers (op-amp) can work at RF. I wonder whether an Op-Amp (e.g. VOA, OTA, CFA, CC) can do this job or not ? If not, at about 2 GHz, are there such current amplification circuits which can mainly amplify the current (with small small voltage gain), or voltage amplification circuits which can mainly amplify the voltage (with small small current gain) ?

At RF frequency, typically at about 2 GHz, I cannot find such amplification circuits which can independently (or mainly) amplify the "current" or "voltage", respectively. Doesn't anyone have an idea or any comments? It is an imperative duty! Thanks!

What about a CC BJT or Mosfet as the voltage amplifier.
A CE or CB as the current amplifier.

The problem consists in that you cannot reasonably MEASURE independently the voltage or current above ~500 MHz in a circuit.
You can calculate both quantities but the only quantity you can really measure is the power. In microwave technology, the above fact is used to derive all other quantities from power and its ratios: the S-parameters, VSWR, etc.

Also at lower frequencies, it's not correct to say that current and voltage can be amplified independently. They are always linked by circuit impedances. The point is however, that you can have circuit impedances ranging from milliohm to Gigaohm. Respectively you can have amplifiers, that are ampliying voltage or current selectively, but not independently. An amplifier with a low input impedance and high output impedance is the prototype of a current amplifier (e.g. a transistor in common base circuit) and the opposite case a voltage amplifier (e.g. a common collector stage). These behaviour will partly work even at GHz frequencies (e.g. inside a chip) but the possible impedance range will be much more restricted, e.g. between a few ohm and some 100 ohm.

Thanks for your reply. I heard that amplifying voltage and current selectively can be easily realized by using CMOS technology. Is that right? I am sorry I have no experience in IC/CMOS design.