11GHz ECLIPSE ODU300 - HARRIS STRATEX |
11GHz Eclipse ODU300 Harris Stratex microwave radio data link was available on Ebay as decommissioning equipment. Compared with Alcatel ODU300, it has almost same arhitecture but Tx, Rx, PLL and waveguide coupler are individual built.
I did some researches about dual PLL module which can be reused for microwave beacon, local oscillator or similar application. Together with YO4RHY, we succeed to reverse engineering & testing the board.
Synth 11GHz RX/TX (PN: 131-141905-304)
Rx/Tx PLL chains are identically, only the frequency range is different, both are designed around LMX2326 PLL IC and patented low phase noise VCO (S53MV).
Internal VCO tuning lock range: Rx = 2310...2540MHz, Tx = 2160...2348MHz. The signal is multiplied X4 and then amplified/filtered. RF output is disabled in case of unlock condition.
LO output Rx= 9.24...10.16GHz and Tx =8.64...9.39GHz.
Both LMX2326 ICs are sharing same Clock and Data SPI lines. During PLL registers update, chip selection is done according the state of Rx Latch or Tx Latch lines.
uC software is based on Arduino IDE. Any Arduino board can be used but I prefer Attiny24/45/85 series. LMX2324 registers are calculated using Code Loader 4 software. Declared stability +/10ppm, TCXO reference oscillator.
Various phase detector references were tested, locked loop obtained for 25..2500KHz (charge pump gain LOW), integer step of 10MHz reference. According Stratex brochure, synth step is 250KHz.
Up-Converter Tx (PN:131-142075-001)
Tx up-converter is a classic architecture and is suitable for 10GHz. Output power is controlled by FI level through PIN diode attenuator & DS1089 electronic potentiometer. Bias point of PA FET is adjusted automatically to "class A" using close loop regulator. Ids quiescent current is very stable against temperature changes and the positive Igs behavior (due to large RF input) is eliminated (read AN010 GaAs FET Bias or TRW amplifier 1986 p46-47).
Down-Converter Rx (PN: 131-142039-005)
Not yet tested/investigated.
FET transistor marking P18 = EPA018A-70
Similar 13GHz version PLL was tested (PN: 131-141905-305). Original range RX: 10.75...11.85GHz and TX: 10.44...11.46GHz. VCO is internal multiplied by 6. Output level ~6dBm.
RX PLL section can be retuned for 12.024GHz by cutting the microstrip resonator and installed 100pF capacitor. Useful output for 24.048GHz signal source.
TX PLL section can be retuned for 10.368GHz using one layer of KAPTON on top of VCO resonator.
RX internal view
Schematic RX Eclipse
TX internal view
Schematic TX Eclipse
F5DQK TX 10GHz testing (link)
PLL internal view
Schematic Dual PLL Eclipse
Schematic SPI Attiny Controller
Arduino sketch dual LMX2326 v.2
