Antenna Working Group
Outline of Design Report for Tianlai Meeting 15-19 July, 2013
Videoconference Summary 10 June 2013
Boldfaced names below are asked to post additional information.
Dish Antennas
- baseline is on-axis, 6 meter diameter
- mechanical design - 2- axis mount (alt-az mount?) designed by
Prof. Shi.
- can we post a design on the website?
- current construction plans:
build 16 on-axis dishes (Institute 54 and Institute 23 may build them)
order this month. plan to have on site next year.
- simulated beam patterns vs frequency
Tao Liu has already done this using TBD software…
Chris Anderson is working on this at UW using Microwave Studios CST
- default feed is four-square
Cylinder Antennas
- on-axis vs off-axis
- mechanical design for each case -
Zhipeng Chen
- current construction plans?
- simulated beam patterns/sidelobes vs frequency in both on and off-axis cases
Tao Liu is working on this
Chris Anderson is also working on this
- need to simulate the effect of beam blockage by feeds in the on-axis case
- default feed is four-square (MOST and CHIME use 4-square)
- we should consider orienting feed axis at 45 degrees to cylinder axis for symmetry
- we should consider feed x-talk and spacing. do we combine in groups of 4?
Feeds
- simulated 4-square beam patterns
-
Tao Liu has done this
-
Chris Anderson and Aleks Cianciara are working on this at UW
- CAD drawings of feed would be helpful -
Yougang Wang & Fengquan Wu
- measured 4-square beam patterns
- has this been done?
- UW group plans to do this
- simulated impedance/ matching to LNA
- has
Tao Liu done this?
-
Chris Anderson plans to do this
-
Peter will ask
Jeff for advice
- are there other feeds we should consider for either dishes or cylinders?
- solar radio group is using a wideband feed from Sweden (like ATA feed?)
LNAs
- Institute 54 has built and tested 4 amplifiers
- these are being modified by Institute 54 now to work in our desired frequency range
- what is current design in China? Need to post the designs on the NAOC website if possible -
Yougang Wang and Fengquan Wu
- has LNA been tested? Need to post gain, S parameters on NAOC website.
Yougang Wang and Fengquan Wu
- LNA been integrated with 4-square feed.
Signal Transport to Correlator
- TV cable tests of phase vs temperature and bending has been performed at NAOC (
Yougang Wang and Fengquan Wu)
- RF cable tests?
- RF over fiber?