Receiver Lab Talks: 2025
Questions: Edward Tong
Time: Thursday 12:00 PM EST/EDT
Where: M-340/Zoom
| Date | Speaker | Title | Summary |
|---|---|---|---|
| Jan. 30 | Sara Issaoun CfA |
Frequency Phase Transfer for (sub)millimeter VLBI | Frequency Phase Transfer (FPT) is a key technique to increase coherence and sensitivity in radio interferometry via the use of non-dispersive phase solutions derived at lower frequencies to calibrate higher frequencies. While this technique, pioneered by the Korean VLBI Network, is readily used at frequencies under 130 GHz, it remains largely untested in the (sub)millimeter regime. Over the last two years, an effort has been made to outfit dual-band systems at (sub)millimeter observatories participating in the Event Horizon Telescope (EHT) and to test the feasibility and the performance of FPT up to the 1.3mm observing wavelength of the EHT. In this talk, I will present the status and results of simultaneous dual-frequency VLBI observations carried out and the applications of this technique to ongoing and future projects. |
| Jan. 16 | Edward Tong CfA |
Receiver Linearity Considerations: How to measure gain compression accurately | Astronomical receivers typically handle very weak input signals. With the development of ultra-wideband receivers and the neccessity to calibrate them using a relatively warm black body, there is a risk that the receiver may operate outside its linearity range. The most prevalent issue is gain compression, which occurs when a receiver component's gain is reduced by large input signals. In this presentation, I will detail a technique for accurately measuring low-level gain compression in both amplifiers and mixers, ensuring the linear operation of receivers |
Previous presentations available here:
CfA managed Google Drive
