dc.description.abstract | In this thesis, two different microwave amplifiers were designed by using monolithic microwave integrated circuit (MMIC) and flip-chip technology for V- and Ka-band applications, respectively.
A V-band MMIC amplifier was realized by WIN 0.15 um pHEMT process. The passive components including matching networks and bias circuits were designed and fabricated by coplanar waveguide (CPW) topology. The design method of two-stage amplifier utilized load-pull simulation to find maximal output power (Pout) for output matching network at second stage and adopted complex conjugate matching to derive sufficient gain for input matching network at first stage. The operating frequency was at 62.8 GHz with scattering parameter S11, S22 and S21 of -2.59 dB, -16.40 dB and 13.33 dB, respectively.
Secondly, a microwave integrated circuit using flip-chip technology for Ka-band is presented. In the application of the microwave circuit, the wire bonding connection could produce serious parasitic effect in high frequency. Therefore, it is important to use flip-chip bonding. At first, flip-chip bump model was developed, and then Ka-band amplifier by using flip-chip technology was designed and fabricated. The active device (0.15 um pHEMT) was fabricated by WIN semiconductor, and the passive components were mainly utilized by CPW to integrate with BCB and fabricated on the alumina substrate. The operating frequency was simulated at 38 GHz, but the measured results show a 6 GHz difference. The possible reasons may result from the variation from the passive component process, RF pads model and flip-chip bump model. The measured small signal parameters S11, S22 and S21 were -5.56 dB, -5.87 dB and 10.49 dB, respectively. In the power performance, the linear gain was 10.59 dB, output power at 1 dB compression point was 17.53 dBm and PAE was 10.27 %. If RF pads model parameters are tuned, it showed good agreement between simulation and measurement. By the realization of the presented Ka-band flip-chip assembly pHEMT circuit, it is possible that the passive components made on separate substrates and flip-chip technology could apply successfully to the high frequency circuits. | en_US |