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Radio Frequency Transceiver Design

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					Radio Frequency Transceiver
          Design

            Heidi L. Lagares
            Advisor: Rafael Solis
Introduction

   Microwave engineering involves circuit analysis
    and design, in contrast to the field theory
    orientation of a generation ago.

   Microwave Engineering is not only apply
    sophisticate mathematics.
Radio Frequency Transceiver Design

   A transceiver is a combination
    transmitter/receiver in a single package.
   Some are design to allow reception of
    signals during transmission periods.
   An RF transceiver is propose as an
    alternative to test design through a wireless
    RF link.
Block Diagram of a RF transceiver
Radio Frequency (RF)

   RF is a term that refers to alternating current
    (AC) having characteristics such that, if the
    current is input to an antenna, an
    electromagnetic (EM) field is generated
    suitable for wireless communications.
   Examples: Cordless and cellular telephone,
    radio and television broadcast stations,
    satellite communications systems.
Analysis

   The analysis of RF transceiver will be
    performed using electromagnetic simulator.
   The design will resonate at 5.85 GHz, and
    with a bandwidth of 125 MHz.
    –   Maximum Gain Amplifier
    –   Low Noise Amplifier
    –   Mixer
Maximum Gain Amplifier

   Amplification is one of the most basic and
    prevalent communication circuit functions.

   The overall gain of an amplifier will be
    controlled by the gains GS and GL (input gain
    and out gain respectively).
Maximum Gain Amplifier Results


   The maximum gain
    amplifier has gain of
    15.6 dB.
Low Noise Amplifier

   An important design for amplifier is the noise
    figure.

   A low noise was designed with a GaAs field
    effect transistor operating at the desired
    frequency.
Low Noise Amplifier Results


   As the graph shows,
    the amplifier gain is
    13.7dB.
   S11 (black marker)
    is at -4.7 dB.
Mixer

   Mixers use nonlinear device to achieve
    frequency conversion of an input signal.
   When signals of different frequencies are
    applied to such a device, the output contains
    not only the original frequencies but also
    frequencies equal to the sum and difference
    of the original frequencies.
Structure of the mixer design

   This is the basis structure of the mixer
    design.

RF                       Matching
              Rat                                     IF
                         network          LP Filter
LO           Race
          (180 hybrid)   Matching
                         network

                  Singly Balanced Mixer
Mixer Design

            RF     IF


      fRF        LO
                        f RF  f LO   f RF  f LO




                  fLO
Mixer Results


                                                  Spectrum at IF port, dBm
   The conversion gain                 60


    is -25dB (the first                 40




                          IF_spectrum
                                        20
    impulse at 0GHZ)                     0

                                        -20

                                        -40
                                              0   2     4      6        8   10   12
                                                            freq, GHz
Radio Frequency Transceiver
Conclusion

   Researchers, designers and students work in
    the development of complex data processing
    and modulation circuits using DSP
    development kits.
   They should test their designs in a more real
    environment and transmit and receive data
    acoustically.
Questions?

				
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posted:5/17/2012
language:English
pages:17