1. Tests of STO IF Components S. Weinreb April 15, 2009 Two 1-2 GHz IF amplifier plates and one 5 GHz converter plate for the Texas test flight have been assembled and tested. Components for six more IF amplifier strings are on hand for the Antarctic flight.

2. STO IF Amplifier Plates Test data on SN1 shows noise output power spectrum with input terminated and DC supply at 5.0V (310mA) and 4.0V (300mA). Resolution 1 MHz, total output power of -25.1 dBm, and monitor detector output of -1.83 mV. Expected input signal of -60 dBm/GHz will raise these levels by 20 dB. There are 10+6 dB pads between the two 38 dB IF amplifiers. Test data on SN2 is almost identical with -25.3 dBm output power and monitor detector output -1.98mV at 5.0V DC.

3. Test Setup for 5 GHz Converter Rohde and Schwarz 4-port network analyzer is used to provide 6.5 GHz LO and measure conversion gain shown on next slide. A 5 GHz bandpass filter will be added at input by U. of Arizona.

4. STO 5 GHz Converter Plate, April 15, 2009 Test data shows conversion gain (~18 dB) with +7 dBm LO at 6.5 GHz and also with 0 dBm LO power. RF input was 4 to 6 GHz giving 2.5 to 0.5 GHz IF out. For -5 dBm output, -23 dBm input power is needed. There are 3 dB pads at RF input and IF output of mixer.

5. Calibration Curve for Monitor Detector At design IF output of -5 dBm detector output is -100mV.

6. Parts for Six More IF Amplifier Plates Amplifiers, power splitters, attenuator pads, and cables to be combined with Lorch filters and packaged in a receiver box for the Antarctic flight. Some additional cables and pads will be required.