Browsing by Author "Wu, Jing-Cheng"

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The Design of Wideband DC-35 GHz IF Modules for 78-113 GHz Receiver Array
(2012-01-01)
Teng, Hsiao-Feng
;
Wu, Jing-Cheng
;
Chiueh, Tzi-Hong
;
Hu, Robert
;
交大名義發表
To facilitate simultaneous detection of the 78-113 GHz millimeter-wave electromagnetic spectra, compact DC-35 GHz IF modules have been designed where the down-converted signals will be divided and further transformed into four 8.7 GHz bands, thus suitable for fiber-optics signal transfer and digital-signal processing. This paper will detail the design methodology and related microwave circuits that constitute the wideband modules; measured results will also be presented. In additional to the intended radio-astronomical instrumentation, this work can be used in applications such as geographical remote sensing and human biological sensors.
Ultra-broadband IF/LO system of NTU W-band interferometer array
(2010-01-01)
Teng, Hsiao-Feng
;
Wu, Jing-Cheng
;
Li, Huan-Hsin
;
Chiueh, Tzi-Hong
;
Niu, Dou-Chih
NTU-Array is designed for W-band (78-113Ghz) interferometric observations of Sunyaev-Zeldovich effects. The first phase operation of the telescope with 6 receivers had its first light in 2008 with single-polarization and half the full bandwidth. The second-phase operation of NTU-Array in Nevada will begin the dual-polarization, full-band observation in 2010. One-bit sampling at 18Ghz and digital correlation are in use in this telescope. Due to the ultra broadband coverage, the IF system divides the 35GHz full-band into four 8.7GHz sub-bands. The first stage of IF module containing a 35GHz broadband amplifier with fairly flat-gain performance over 25db gain divides the first-stage IF into two outputs. The 2nd-stage IF module further divides the two input IF signals and down-converts them to four basebands of DC-8.7Ghz. An LO module with 8.7Ghz input is to generate outputs with x2, x3 and x9 harmonics for the down-conversion. The Walsh function is injected into the x9 LO via an IQ mixer. Each IF baseband is transmitted through an optical link to the 18Ghz, 1-bit sampling ADC located in the control room. The analog optical link contains a driver and equalizer to compensate for the path loss. Considering the limited size of the telescope mount, the entire IF/LO system of each receiver has a compact size about 20cm cubed. This physical size can be further reduced to fit the future 19-pixel-receiver upgrade of NTU-Array