Dong-Pil Chang

Ka-band LNA module with 1.9dB NF for communications satellite payload

A LNA module, integrated microwave assembly was developed for Ka-band communications satellite payload in the frequency range of 29.6 /spl sim/ 30.0 GHz. The noise figure of the module has been recorded as low as 1.9dB at ambient temperature. The module has been tested over temperature range of -15 /spl sim/ +71/spl deg/C and shows 33.3dB of gain within 0.7dBp-o variation as it has the function of gain compensation. The mass of the module is 94grams that provides the flexibility in payload assembly. Two low noise amplifier MMIC chips were used in the module and those chips had been fabricated using 0.15 /spl mu/m GaAs pHEMT process. This paper describes the design, fabrication and performance of the LNA module. This will include the MMIC design, the mechanical design of module, and the design of waveguide-to-microstrip transition.

Wideband characterization of multiple bondwires for millimeter-wave applications

Wirebonding is a common interconnection for modern microwave devices because of the rather simple and reliable processes involved. At millimeter-wave frequencies, however, the bondwire parasitics are significant and consequently limit the external performance of packaged devices. In this paper, we represent wideband characterizations of single, double, triple bondwires in a frequency range from 20 to 35 GHz. The measured results show that the double bondwire is comparable to the ribbon in terms of the insertion loss, and the wirebonding is very suitable for millimeter-wave packaging by virtue of the performance and the manufacturing cost.

Development of a receiver downconverter module for Ka-band satellite payload

This paper describes the design and the test results of the receiver-downconverter module for a Ka-band Satellite Payload. The developed module has the low noise amplification in front stage and frequency down conversion which translates from 30.6 GHz - 31.0 GHz to 20.8 GHz - 21.2 GHz.. It has been fabricated and tested by the qualified satellite component manufacturing process and it shows the best performance of the receiver-downconverter modules operating at Ka-band frequency up to date. The module has the performance of 1.9 dB of NF, 55 dB of Gain, and 57 dBc of C/13 for the two-tone signals of -59 dBm input power, respectively, at ambient temperature. It is a small and light module with the size of 93 mm /spl times/ 84 mm /spl times/ 26 mm and the weight of 240 g.

Design of High Performance HEMT Switch for S-band MSM of Satellite Transponder

A SPST switch MMIC which used for microwave switch matrix (MSM) of communications satellite payload with multi-beam function has been designed and fabricated. New RF FET switch configuration has been devised to improve power characteristics and isolation. Input and output return losses are better than another switches reported previously for both on and off states. The MMIC chips were fabricated in 0.15 um GaAs pHEMT process and measured insertion loss less than 2.0 dB and isolation more than 63 dB in the frequency range of 3 GHz ~ 4 GHz. Output 3rd order interceptpoint above 32 dBm has been recorded and the value is very high even though the unit pHEMT has gate width of 0.2 mm and only four pHEMT are used in the MMIC.

Wideband Receive Antennas of Sensor Stations for GPS/Galileo Satellite

This paper describes wideband L-band receive antennas of sensors for GPS as well as Galileo satellites. The antenna should provide small variations of the phase center and small group delay variations. In order to meet the specification on antenna gain, conical spiral antenna is considered. A conical spiral is arranged in a circular cylindrical cavity. The spiral is composed of bifilar coaxial line. These coaxial lines are matched to 50 Omega coaxial cable by using 1:4 RF transformer and balun. The antenna gain at zenith is greater than 6 dB and the minimum gain at low elevation angle is about -3 dB over lower frequency bands (El and E6 bands) but that is -3.5 dB over high frequency band (LI). The phase center variation of the antenna is less than 4.3 mm over whole operating frequency bands. The antenna has good performance characteristics.

A 26.4 GHz phase locked oscillator for space application

A 26.4 GHz phase locked oscillator (PLO) for communication satellite is fabricated. The PLO consists of two parts - Fundamental Frequency Generation Module (FFGM) and Frequency Multiplication Part (FMP). FFGM generate highly stable 8.8 GHz oscillating signal using VCDRO and SPD. Frequency tripling process occurred in the FMP. MMIC tripler and amplifier are used for the reduction of the size and mass of FMP. The phase noise of 26.4 GHz PLO is exhibited as -96 dBc/Hz at 10 kHz offset frequency and -105 dBc/Hz at 100 kHz offset frequency, respectively, with the output power of over 11 dBm.

High Output Power and High Fundamental Leakage Suppression Frequency Doubler MMIC for E-Band Transceiver

An active frequency doubler monolithic microwave integrated circuit (MMIC) for E-band transceiver applications is presented in this letter. This MMIC has been fabricated in a commercial 0.1- ㎛ GaAs pseudomorphic high electron mobility transistor (pHEMT) process on a 2-mail thick substrate wafer. The fabricated MMIC chip had been measured to have a high output power performance of over 13 dBm with a high fundamental leakage suppression of more than 38 dBc in the frequency range of 71 to 86 GHz under an input signal condition of 10 dBm. A microstrip coupled line is used at the output circuit of the doubler section to implement impedance matching and simultaneously enhance the fundamental leakage suppression. The fabricated chip is has a size of 2.5 mm X 1.2mm.

Design of Ku-Band BiCMOS Low Noise Amplifier

A Ku-band low noise amplifier has been designed and fabricated by using 0.25 um SiGe BiCMOS process. The developed Ku-band LNA RFIC which has been designed with hetero-junction bipolar transistor(HBT) in the BiCMOS process have noise figure about 2.0 dB and linear gain over 19 dB in the frequency range from 9 GHz to 14 GHz. Optimization technique for p-tap value and electro-magnetic(EM) simulation technique had been used to overcome the inaccuracy in the PDK provided from the foundry service company and to supply the insufficient inductor library. The finally fabricated low noise amplifier of two fabrication runs has been implemented with the size of . The pure amplifier circuit layout with the reduced size of without the input and output RF pads and DC bais pads has been incorporated as low noise amplication stages in the multi-function RFIC for the active phased array antenna of Ku-band satellite VSAT.

Practical Method for Obtaining Maximum Channel Temperature of GaAs MMIC

[Abstract] Regressive equations that calculate the maximum channel temperature of a GaAs monolithic microwave integrated circuit (MMIC) have been made through a lot of finite element (FE) analyses. And this paper suggests how to estimate the maximum channel temperature with those regressive equations for frequent cases. As an example, a medium power amplifier’s maximum channel temperature was calculated and its result was larger than that of a complete FE model by about 4%. The medium power amplifier’s temperature distribution was obtained through an infrared scan and, even though the maximum channel temperature could not be obtained due to the test’s inherent shortcoming, temperature other than gate fingers showed good agreement with FE analysis results. Therefore it can be said that the practical method for obtaining the maximum channel temperature using regressive equations can give thermal resistance of a GaAs MMIC very easily and quickly without time-consuming FE analyses.

GaAs MMICs for use in upconverter module for Ka-band OBS satellite transponders

GaAs MMICs has been developed for use in the Upconverter module for On-Board Switching Ka-band Satellite Transponders. There are four kinds of MMICs: an S-band Medium power amplifier, a K-band Medium power amplifier, an S to K-band Mixer, and X to Ku-band frequency doubler. The four chips have been fabricated on a wafer using 0.15/spl mu/m GaAs p-HEMT technologies. A Upconverter module using the MMICs with a function of the frequency conversion from 3GHz to 20GHz has been developed and showed the RF performance of the 17.1/spl plusmn/0.2dB conversion gain, the 0.2nsp-p group delay, the 46.67dBc C/IM/sub 3/, and 1.15:1 In/Out VSWR.