The mm-Wave and THz CMOS IC Design Course was held January 11 through February 4, 2022 virtually from the University of Limerick. The short course consisted of eight 1.5 hour lectures followed by a half hour question and answer session taught by Professor Patrick Reynaert from the University of Leuven (KU Leuven), Belgium.
Course Program
The topics and outlines for each lecture are shown below. I particularly liked Lecture 4 on transformer matching circuits with differential gains stages to construct Power Amplifiers (PAs) and Low Noise Amplifiers (LNAs).
- Lecture 1: System-level challenges of mm-wave systems
- mm-wave challenges: Silicon technology evolutions, Free space path-loss, and Beamforming
- Distortion: Spectral mask, Constellation and EVM, and PAPR definitions
- Noise and phase-noise.
- Lecture 2: CMOS transistors at mm-wave
- MOS transistor power gain, fT and fMAX
- Gate resistance
- Stability
- Neutralization
- Drawback of Neutralization
- Technology comparison
- Lecture 3: CMOS Passives at mm-Wave frequencies
- Metal stacks, CMOS vs SiGe and Q-factor
- Capacitors
- Inductors
- Transformers
- Transmission lines
- Shielding
- Lecture 4: Building blocks
- Design of transformer based matching networks
- Minimize loss: GA and GP circles
- Maximize bandwidth
- 77GHz LNA in 28nm CMOS
- 77GHZ RX in 28nm CMOS
- D-band VCO in 16nm FinFET
- 120GHz TX in 65nm CMOS
- 390GHz TX in 28nm CMOS
- Design of transformer based matching networks
- Lecture 5: mm-wave PA design in CMOS
- Challenges for mm-wave CMOS Pas
- 140GHz Common-Source PA in 40nm CMOS
- 140GHz Common-Source PA in 16nm FinFET
- 77GHz Common-Source PA in 40nm CMOS
- 77GHz Cascode PA in 40nm CMOS
- 60GHz complementary PA in 40nm CMOS
- 77GHz Matrix PA in 22nm FDSOI
- 60GHz Dual mode PA in 40nm CMOS
- 77GHz Doherty PA in 40nm CMOS
- Lecture 6: The Secrets
- Imbalance in transformers
- Importance of VDD and bias networks
- Ground versus Reference
- Stability considerations, K-factor, PZ-identification
- Drawbacks of neutralization
- Measurement mistakes
- Lecture 7: Polymer Microwave Fibers
- PMF concept
- Comparison between PMF, optical and copper
- PMF channel
- PMF coupler
- PMF chips
- Better SNR
- Lower dispersion
- Duplex operation
- Recent results
- SFP28 development
- Lecture 8: THz in CMOS
- Above-fmax operation
- Early experiments in CMOS
- Efficient power extraction
- On-chip 3D printed horn antenna
- Beamforming experiments
- 600GHz RX
- 400GHz phase imaging setup
Recommended Reading
- RF Signal Chain - Properties & Performance Metrics
- RF Signal Chain - Essential Building Blocks
- RF Impedance Matching - Calculations & Simulations
- S-Parameter Design
Simulator
We had two homework assignment using the Quite Universal Circuit Simulator (QUCS). QUCS is interesting because you can construct microstrip and strip line transmission lines, perform S-parameter simulations, and run harmonic balance simulation.
In two homework assignments, we simulated the amplifier stability for various values of neutralization capacitance. Then, we simulated effects of ground capacitance imbalance in a transformer with varying amounts of neutralization capacitance, and explored the stability of the transformer with an amplifier using K or Rollet Factor with variation in the components of passive input and output matching networks.
Acknowledgements
I enjoyed this course. I appreciate Professor Reynaert for teaching the course, and Hooman Reyhani for his efforts organizing the course.