In this episode Shahriar reverse engineers an ADI GaAs 81-86GHz I/Q Down-Converter MMIC. The receiver includes a x6 LO multiplier chain and direct-down-conversion architecture based on pHEMPT single-balanced mixers using fundamental LO frequency.
The RFIC block diagram & die are examined in detailed. The live microscope images are annotated with signal flow drawings to describe various implemented blocks and IC functions.
In this episode Shahriar looks at the ecosystem of R&S power sensors & power meter. In particular, the NRP Triple-Diode Path Power Sensor & the unique NRQ6 Frequency Selective Power Sensor:
In this episode Shahriar repair a Tektronix high voltage probe. The probe is incorrectly identified when plugged into a TekVPI interface and causes the scope to freeze and fail communication with the probe firmware.
With the help of xDev.com the firmware of the probe is compared with a known good probe.
The probe contains two different microprocessors to handle various probe functions and configurations. The new EEPROM content corrects the problem and points to some interesting conclusions on how the probe is identified by the scope. Measurements confirm the probe is now functional.
In this episode Shahriar returns to the microscope LED upgrade challenge. The highest light density LED is used as a point source to improve Kohler illumination. Both transmission & reflected light sources are upgraded while maintaining the control purely through the microscope controls. The LED used can be found here:
In this episode Shahriar takes a look at a Stanford Research SR630 16-Channel Thermocouple Monitor. This instrument provides accurate temperature readings multiplexed from 16 unique inputs. It also supports a wide range of thermocouple types. The instrument is purposely not powered on initially as it is prone to capacitor leakage on the main board. The capacitors have destroyed many of the crucial traces all of which have to be individually replaced with wires.
Repair is successful and the instrument is back to life! To test the unit, the temperature on both surfaces a Peltier cooler is measured. The thermoelectric pump is able to cool one side to below -5C while consuming 3.5W.
The Signal Path (TSP) is a science & electrical engineering video blog for industry professionals, researchers & students. TSP is a not-for-profit website dedicated to provide free education spanning a wide range of electrical engineering & science topics. Equipment reviews, tutorials and repair videos are posted regularly.
