Advanced RFIC Design ELEN359A, Lecture 4: Frequency TranslationInstructor: Dr. Allen A Sweet

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Types of Frequency Translation

• Multipliers: No LO signal required, but High power drive signal is required (I.e. high DC current), high conversion loss.

• Translators: Convert any frequency to any other frequency, either up or down. Low drive power (low DC current), conversion gain. Requires a stable LO signal (PLL).

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Types of Multipliers

• Differential to Single Ended Diode Doublers

• Full Differential Diode Doublers• Single Ended Diode Tripler's• Gilbert Cell Doublers• Gilbert Cell Tripler's

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Diode IV Characteristics

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Diode Curve Schematic Diagram

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VBIC Diode IV

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Single Ended Diode Doubler

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Half sine Waves are Rich in secondHarmonic

ADS Model of a Single Ended Diode Doubler

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HB Controller and Sources for Diode Doubler

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ADS Simulations of a Single Ended Diode Doubler

Pout @ 2FIs 0 dBm

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Differential Diode Doubler

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ADS Model for a Full Differential Diode Doubler

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HB Controller and Sources for Differential Diode Doubler

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ADS Simulation of a Fully Differential Diode Doubler

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Pout @ 2F Is 0 dBm

(Requires a+20 dBm Drive signalWhich takes100 mA DC Current at 30% eff)

Single Ended Diode Tripler

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ADS Model for a Single Ended Diode Tripler

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HB Controller and Sources for Diode Tripler

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ADS Simulation of a Single Ended Diode Tripler

(No naturalSuppression ofFundamental)

Symmetric Clipping of Wave form byBack to backdiodes

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Gilbert Cell Doubler

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ADS Schematic of a Gilbert Cell Doubler

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Source Configuration

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HB Controller Setup

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Gilbert Cell Doubler SimulationMany mixingProducts Contribute

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Simulated Gilbert Doubler by “Hard Wiring” RF and LO ports

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Simulation of “hard wired input” Gilbert Cell Doubler

(Add 3 dB to include LOSignal loss:gain=-4.287)

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Gilbert Cell Tripler

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Sources and HB Controller for Gilbert Cell Tripler

RF_freq=2 X LO_freq

(Use high order)

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Simulation of Gilbert Cell Tripler

Many mixer productsContribute to tripling

Translators

• No harmonic relationships between the input and the output Frequencies.

• Up Converting Translators• Down Converting Translators• Requires a PLL LO Signal

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Gilbert Cell Down and up Converters

(i.e. +/-F2+/- F1)

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Translate Wi-Fi (B) Down to Wi-Fi (A) with a Gilbert Cell Mixer

(Use high side LO)

Flo=Frf + Fif=2.5 GHz + 5.5 GHz=8.0 GHz

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Sources

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Output BPF

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ADS Simulation of Down Converting Wi-Fi Translator

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Up Convert Cellular 850 MHz to PCS 1900 MHz

Flo=-Frf + Fif = .85 + 1.9 = 1.05

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Sources

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BPF at the Output

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ADS Simulations of Up Converting Frequency Translator

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Homework #4: Simulate a Wi-Fi Frequency Translator

• Design an Up Converting Frequency Translator from Wi-Fi A (2.4 GHz) to Wi-Fi B (5.8 GHz). The Translator shall have at least 25 dB gain, requiring either a pre or a post amplifier.

• All Spurs from 3.0 GHz to 7.0 GHz will be down by at least –40 dBc. You must design the filter.

• Make design decisions on the basis of lowest possible DC current.

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