Mackenzie Cook Mohamed Khelifi Jonathon Lee Meshegna Shumye Supervisors: John W.M. Rogers, Calvin Plett 1

 Motivation and Applications  Block Diagram 2

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Meshegna Shumye LNA

 Requirements:  Good Gain  Low Noise  Good Linearity  Input Matching LNA Schematic

Gain = 18dB NF = 3.8 dB

P 1dB = -68dBm IIP3 = -52 dBm

220u

Mackenzie Cook 9

 Traditional Superheterodyne Architecture ◦ High Order Filtering ◦ Off Chip Requirements  Quadrature Feedback Channel Selection at RF ◦ First Order Filtering ◦ Significantly Reduced Off Chip Requirements 10

 20dB Stop Band Rejection  5dB Adjacent Channel Rejection  200kHz channel spacing at MHz  150kHz bandwidth  Tunable Channel Selection via Local Oscillator  Differential Operation 11

Desired Channel Mixed to 0Hz Desired Channel Removed Interference Amplified - 12

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100MHz Passed Adjacent Channel 11.3dB Rejection Peak Rejection 18.6dB 15

2.2mm 1.8mm 16

Mohamed Khelifi 17

 Context: a local reference is fundamental to RF design.  Why: Reference frequencies for signal manipulations  Solution: a set of electrically tunable oscillators Channel Select Filter Channel Select Voltage Control Oscillators HF LF FM Demodulator Reference Signal Generator Local Oscillator: The Story 18

 Delay In Each Stage + Negative Feedback = Oscillation  Minimum stages = 3  Highest Frequency so Far ◦ 460 MHz before tuning ◦ Tunable down to 380 MHz (voltage controlled C’s). Ring Oscillator 460 MHz Sinewave Local Oscillator: The Solution 19

 Frequency divide-by-2 FlipFlops  Advantages ◦ Squarewave - easier to work with ◦ Four Phases for the Channel Select ◦ Frequency error also divided down  Disadvantage – Size increase due to dividers 115 MHz Squarewave Local Oscillator: The Optimization 20

 IC Area  Overall Integration – Cannot use resonator (C and L)  Varying LO Demand from µFM components Local Oscillator: The Challenges 21

Jonathon Lee 22

FM Demodulation FM Demodulation -How to extract the information A phase locked loop (PLL) can be used for FM demodulation idid R C1C1 C2C2 V DD PFD Loop Filter Voltage Controlled Oscillator Phase Frequency Detector VCO UP DN Charge Pump FM Signal Demodulated Signal In Summary: The PLL, through feedback, tracks the frequency of the FM signal. The control voltage of the VCO is the demodulated signal. PLL 23

Circuit Layout Phase Frequency Detector (PFD) Charge Pump Loop Filter (Off chip) VCO 24

PLL – Acquisition and Lock Blue Waveform (Input): 50 kHz pure sine wave Red Waveform (Output): The output of the demodulator The first 95 µs are the start-up transient as the PLL acquires lock Lock range (11.88 MHz – MHz) f c = 12.5 MHz Time (µs) Voltage (V) 25

 Design – No PMOS transistors (NMOS only)  Simulation – Initially no models for 2.5 µm NFETs  Layout - Single metal layer 26

 Completed design and fabrication of 7 RF circuits  Generated and updated transistor models for Carleton’s Process  First group ever to design 2.5 µm circuits using Carleton’s Process 27

RF Probes Team: Remaining Work Testing the silicon 28

 Two possible paths: 1.Create a product:  Connect all ICs on chip  Select:  Power supply  Antenna  Audio amplifier  Product packaging 2.Further Research:  Further integration of off-chip components  Optimization (layout and circuitry)  Higher frequency applications 29

Thank you for your attention. Questions?  John Rogers and Calvin Plett  Garry Tarr and Ryan Griffin  Rob Vandusen and Angela Burns 30

Local Oscillator Context: Low frequency => cheaper ; high frequency => better RF performance, smaller size. Need: local reference signals for RF signal manipulations (e.g. RF  low frequency). Delivered: an electrically (voltage) tunable oscillator operating at required frequencies. Optimization: 4-Phase high frequency Squarewave – Better compatibility for PLLs and Channel Select. – Dividers divide down differences errors make. Ring OSC Freq. ÷2 31

Frequency Modulation (FM) In Summary: Amplitude variations of the desired signal are transmitted as frequency variations of the carrier frequency FM Modulator (VCO) Antenna Transmit (Tx) Antenna FM Demodulator (PLL) Receive (Rx) Voice Amplitude Time In Summary: Frequency variations of the carrier frequency are converted to variations in the amplitude of the received signal Time Voice Amplitude 32

2. Designing an NMOS charge pump CMOS CP UP DN UP DN 33

Commercial FM Spectrum (Radio) Commercial FM broadcasting: 101 FM channels located between 87.9 MHz and MHz 200 kHz channel spacing Channel Spectrum: Mono audio between 30 Hz – 15 kHz Stereo audio between 23 kHz - 53 kHz Additional spectrum for services above 53 kHz 34

Layout - Metal Routing 35

Step-by-Step Demod Example 1.Initial Conditions: –Incoming FM frequency is MHz –Loop VCO frequency is MHz Therefore the VCO frequency must increase to match incoming frequency 2.Transient Action: –The PFD sees the mismatch in frequencies and tells the VCO frequency to speed up: I.PFD tells the charge pump to pump more current into the loop II.This increase in current is converted to an increase in voltage by the loop filter III.This increase in voltage is at the input of the VCO –The loop frequency will increase since the output frequency of the VCO is proportional to the input voltage 3.Lock Obtained: –The VCO frequency will now stay locked with the incoming frequency until it changes again! 36

PLL Design Considerations Frequency Response – Natural Frequency (ω n ) Determines bandwidth of the PLL – Damping Coefficient (ζ) Designed to be (critically damped) 37

PLL Waveforms Loop Input Charge Pump Reset 38

PLL Response to 3 MHZ Frequency Step 39