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Technical Description

The tinySA contains all the components of a conventional heterodyne swept spectrum analyzer.

The components used in low input mode are:

  • In low input mode the signal enters the tinySA through the low SMA connector
  • 0-31dB settable Attenuator to protect the RX and prevent internally generated harmonics distortion
  • 350MHz low pass filter to eliminate aliases
  • A TX block that contains the local oscillator to do the scanning of the selected frequency range.
  • The switch is used to enable the tracking output to the high output if activated
  • Mixer that mixes the output from the low pass filter with the local oscillator to create the high IF.
  • Band pass filter at 433.9MHz for the high IF that eliminates spurs and cleans the output from the mixer before the downconversion.
  • A switch to route the output of the BPF to the RX
  • And RX containing
    • Second LO and mixer to downconvert the high IF to a low IF at 870kHz.
    • Selectable resolution filters between 3kHz and 600kHz.
    • Power detector with 120dB dynamic range after the resolution filter.

The components used in high input mode are:

  • In high input mode the signal enters the tinySA through the high SMA connector
  • A switch to route the high input to the RX block
  • An RX block containing
    • LO and mixer to downconvert the selected frequency range to a low IF at 870kHz. Mirror suppression is limited to 30dB
    • Selectable resolution filters between 3kHz and 600kHz.
    • Power detector with 120dB dynamic range after the resolution filter.Local oscillator that does the

The components used in low output mode are:

  • TX block with Local oscillator generating 433.9MHz
  • A switch to route the TX output to the Band Pass Filter
  • Band pass filter removing the harmonics of the 433.9MHz local oscillator.
  • Second TX with local oscillator that determines the output frequency.
  • Mixer that mixes the output from the band pass filter with the second local oscillator to create the desired output frequency with limited harmonics
  • Low pass filter for the low output to remove unwanted mixer products.
  • Output attenuator connected between the low pass filter and the low output to optionally reduce the output level
  • The generated signal leaves the tinySA through the low SMA connector

The components used in high output mode are:

  • Local oscillator that determines the output frequency.
  • A power amplifier with selectable output power between +5dBm and +20dBm
  • The switch connects the power amplifier to the high SMA connector

The calibration generator:

  • 30MHz temperature controlled crystal oscillator
  • Selectable dividers to create 30, 15, 10, 4, 3, 2 or 1 MHZ
  • Fixed voltage output driver
  • High accuracy attenuator to create a 30MHz fundamental of -25dBm into 50 ohm as power reference connected to the high output.
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Page last modified on July 22, 2020, at 09:49 AM