A 56 GHz InP VCO for Use in 112 GBaud (112 GBit/s NRZ or 224 GBit/s PAM-4) InP Integrated Optical Receiver Front-End CDR Block
Bibliographic record
Abstract
This paper presents the design of a 56 GHz voltage-controlled oscillator (VCO) designed in an Indium Phosphide (InP) 0.8 µm kit. InP (III-V) semiconductor technology was chosen since the fastest photodiodes that currently exists on the market (for use with 112 GBaud) make use of InP PIN diodes. The goal is to integrate everything in one die and one technology of InP (including the PIN diode, front-end transimpedance amplifier (TIA), and CDR blocks with the VCO); for this reason InP was used and to assess if such a VCO can be designed for use in 112 GBit/s NRZ (or 224 GBit/s PAM-4) receiving CDR units. The 56 GHz VCO can either be used directly in a half-rate CDR or be used in a full rate 112 GBaud CDR using a frequency doubler circuit. Post-layout electro-magnetic simulations of the VCO had a tuning range of 55 GHz - 58 GHz. The small tuning range is due to the fact that there were no varactors in the InP kit, hence makeshift HBTs with their limited tuning capacitances were used as the core varactors. The VCO used 11.1 mA of current (including periphery circuitry: buffers & current mirrors) from a 3.3 V supply; for a total power consumption of 36.6 mW. The output signal had a phase noise of -98 dBc/Hz at 10 MHz offset (which is comparable to similar InP works). The VCO design used a -gm cross coupled pair that can provide differential oscillation to recover the clock signal from a differential data input. The core size of the VCO (meant to be used as part of a CDR unit) required only 113 µm × 94 µm of layout space.
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How this classification was reachedexpand
Full frame machine prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. The Gemma side is a direct model label for every work in the frame, read from the title-only record. The Codex side is a classifier learned from the 10,348 direct Codex labels and calibrated to design-weighted sample rates; fields without enough sample support carry no Codex call. Candidate is the union of the two sides; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels.
Distilled classifier scores by category (both heads)
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.000 | 0.000 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.000 | 0.000 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.001 | 0.000 |
| Open science | 0.001 | 0.000 |
| Research integrity | 0.000 | 0.000 |
| Insufficient payload (model declined to judge) | 0.003 | 0.001 |
Machine scores (provisional)
The two teacher heads of the student model, read on this work. A score orders the frame for review; it never asserts a category, and the validation status ships verbatim with every row.
Baseline scores from an immature model (maturity gate not passed, 7 training rounds). Scores rank; they never assert a category.
score_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from itClassification
machine, unvalidatedMachine predicted; a candidate call from one source (direct Gemma or distilled Codex), not a consensus.
How this classification was reached, model by model and score by score, is at the end of the page under "How this classification was reached".