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Vector Modulator AMC board. Marcin Smelkowski marcin.smelkowski@desy.de. Presentation is based on „Draft Requirements for a new Vector Modulato On a AMC Card” by Henning Weddig. Warsaw University od Technology PERG – ISE 3.12.07. Purpose of VM board.
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Vector Modulator AMC board Marcin Smelkowski marcin.smelkowski@desy.de Presentation is based on „Draft Requirements for a new Vector Modulato On a AMC Card” by Henning Weddig Warsaw University od Technology PERG – ISE 3.12.07
Purpose of VM board • Changing the amplitude and phase of the 1.3GHz reference signal from the master oscillator. Then modulated signal goes via a preamplifier to the klystron which then drives the accelerating cavities. • The generation of the LO signal for the down converters. • Generation of new frequencies. Marcin Smelkowski marcin.smelkowski@desy.de Warsaw University of Technology ISE - PERG
Block diagram Marcin Smelkowski marcin.smelkowski@desy.de Warsaw University of Technology ISE - PERG
Sub-Modules • DAC – two-channel AD9777 – convertion of digital I and Q signal • Interface Between AD9777 and ADL5385 with 50 Ω resistors to ground to establish the 500 mV DC Bias for the ADL5385 baseband Inputs. Also resistor is placed in shunt between each side of the differential pair. It has the effect of reducing the ac swing to 1.4 V p-p differential without changing the dc bias already established by the 50 Ω resistors. • 5-pole Chebychev filter with a corner frequency of 36 MHz - When driving a modulator from a DAC, it is necessary to introduce a low-pass filter between the DAC and the modulator to reduce the DAC images • Vector Modulator - ADL5385 – 50 to 2200 MHz, Noise floor -159dBm/Hz, Sideband suppression -44dBm and Carrier feedthrough -36 dBm while unadjusted. After optimization Ssup=-50dBm and Cft=-61dBm can be achieved. Callibration can be simply done by adjusting the DAC output currents. By changing the DAC’s registers the levels and offsets of those currents can be control. • 4 x Power Detector – AD8362 Input dynamic range of >60 dB: −52 dBm to +8 dBm in 50 Ω, Linear-in-decibels output, scaled 50 mV/dB They are placed to detect power of LO, RF after amplifier, RF after attenuator and RF after RF-Gate. • Voltage switch - ADG733 + 16 bits ADC with SPI - AD7683 – to make the readouts from choosen power detector. There is no need of making it from all detectors at the same moment. • Low noise amplifier HMC374 – gain of 13dB, low noise figure: 1.5dB, high output IP3: +35 dBm • Attenuator – HMC305 - 0.5 dB LSB Steps to 15.5 dB with control done by SPI • RF-Gate – HMC349 + OR logic gate – high isolation, non-reflective DC to 4 GHz switche plus aditional external logic to calcualate the on/off signal • Leds and SMA inputs/outputs on the front panel (prototype board) Marcin Smelkowski marcin.smelkowski@desy.de Warsaw University of Technology ISE - PERG
Summary • Controller Provides: • - self diagnostic and callibration • in case of carrier break-down sterring signal is taken form Feed-Forward tables in EEPROM • a lot of logic for custom algoritms • on-line mesuare of power at every stage of signal procesing • no output power if the system is off • sending the mesuared values to the main FPGA • diagnostic readouts • Stage of work: • all schematics are already done • layouts are half-made and are expected to be finished by the end of the year • it is expected that by the end of the February the prototype board will have been started and tested • Background: • all schematics of AMC Vector Modulator board were made as a result of research and development of the first version of Vector Modulator board for ACB1 board Marcin Smelkowski marcin.smelkowski@desy.de Warsaw University of Technology ISE - PERG
Thank You For Your Attention, All Comments And Remarks Marcin Smelkowski marcin.smelkowski@desy.de Warsaw University of Technology ISE - PERG