tags:
- ✏️Note
related:
- "[[ECE1390 RF - Wireless RF IC Design]]"
- low noise helps overcome trade-off between impedance-matching and NF
- external matching can save significant amount of power by the following
1.1 Passive Amplification
- scales voltage and current at input of LNA (RF amplification)
- filters out-of-band blockers
- reduces noise for rest of RX chain
1.2 Biasing for Low Voltage Operation
- (left) - requires current source, and large for low noise
- (right) - inductor of matching networks biases common gate
2 Low Power Current-Mode LNA
- suitable for low cost and power applications since it avoids resonant load and can share bias current with other blocks
2.1 Feedback or Feedforward
- synthesizes and Input Impedance () with less than noise
- FB requires RF voltage gain
2.2 NF with explicit termination
2.3 Common Source with L-Matching Network
- noise greater than 3dB but gain boosting proportional to quality factor
- halves bias current for a given
2.5 Inductive Degenerated Amplifier
- noise lower than 3dB and passive amplification
2.6 Common Gate Amplifier
- modest NF without feedback or feedforward
- wideband but with poor transconductance gain
- feedforward reduces noise of transistor by factor of
- low NF
- comparable to inductive degeneration with Q of 1
- high power
- capacitive degenerated
- good quadrature accuracy and modest gain mismatch for narrowband
- CG-CS
- high transistors needed for good quadrature accuracy
