Now showing 1 - 4 of 4
  • Publication
    A channelized sideband distortion model for suppressing unwanted emission of Q-band millimeter wave transmitters
    In this paper, a channelized sideband distortion model is proposed to suppress the unwanted emission of Q-band millimeter wave (mmWave) transmitters in wideband contiguous carrier aggregation scenarios. By employing this model, the compensating bandwidth or center frequency can be agilely controlled. Experiments were conducted on a 40 GHz mmWave power amplifier to validate this idea. The satisfactory performance proved that the proposed model is a promising candidate for future 5G applications.
      156Scopus© Citations 6
  • Publication
    Single-Model Single-Feedback Digital Predistortion for Concurrent Multi-band Wireless Transmitters
    In this paper, a novel single-model single-feedback digital predistortion (DPD) technique is proposed to linearize concurrent multi-band wireless transmitters. By employing carrier relocation and band-limiting functions in digital signal processing, DPD model complexity is significantly reduced and only one narrowband feedback loop is required for data acquisition. In the new system, the linearization bandwidth can be arbitrarily reconfigured, which provides considerable flexibility for DPD system design in wideband concurrent operations. Experimental tests were conducted to validate various cases including a concurrent quad-band scenario that is reported for the first time to date. Excellent performance demonstrates that the proposed approach provides an effective solution for reducing DPD system implementation complexity and cost in both digital and analog domains for future wideband concurrent multi-band transmitters.
      399Scopus© Citations 14
  • Publication
    A SIW-based Wideband Circularly Polarized 4×4 Patch Array Antenna in 45 GHz Band
    In this paper, a substrate integrated waveguide (SIW)-based wideband circularly polarized (CP) 4×4 patch array antenna operating in 45 GHz band is proposed. Firstly, a series-fed 1×4 patch subarray is designed. Sequential rotation (SR) feeding technology is adopted to extend axial-ratio (AR) bandwidth. Then, a 4×4 patch array antenna using four 1×4 patch subarrays is presented. The anti-phase feeding network is used to obtain stable CP radiation patterns among wide frequency band. The proposed antenna was fabricated and measured. -10-dB|S11| bandwidth of 27.6% (36.4-51.2 GHz), 3-dB AR bandwidth of 11.6% (41.6-47.6 GHz) and the peak gain of 17.1 dBic are achieved in the vicinity of 45 GHz.
      107Scopus© Citations 1
  • Publication
    A reconfigurable in-band digital predistortion technique for mmWave power amplifiers excited by a signal with 640 MHz modulation bandwidth
    In this paper, a novel in-band digital predistortion (I-DPD) technique with a reconfigurable coefficient pyramid is proposed to linearize a mmWave power amplifier excited by a modulated signal with very large bandwidth, such as 640 MHz. This method can overcome the multiple bandwidth regrowth issue in conventional DPD operation that normally places a burden on the 5G applications. By employing a coefficient pyramid, the proposed method can efficiently select the necessary core functions to build the nonlinear kernels according to the operation modes, which can largely reduce the power consumption and thus increase the system efficiency. Experimental results with 640MHz modulated signal proves that extending the DPD capability into the forthcoming 5G is possible.
      300Scopus© Citations 3