RESUMEN
A compact Ka-band antenna array has been proposed to realize broadband and high gain for millimeter-wave applications. The antenna array is divided into a multilayer composed of a driven slot patch layer and a parasitic patch array layer, which is excited by a mixed CPW-Slot-Couple feeding network layer. According to characteristic mode analysis, a pair of narrow coupling slots are introduced in the driven patch to move the resonant frequency of characteristic mode 3 to the resonant frequency of characteristic mode 2 for enhanced bandwidth. In this article, a 1to4 CPW-Slot-Couple feeding network for a 2 × 2 driven slot patch array is implemented, and then each driven slot patch excites a 2 × 2 parasitic patch array. Finally, a proposed 4 × 4 × 3 (row × column × layer) Ka-band antenna array is fabricated to verify the design concepts. The measured results show that the frequency bandwidth of the antenna array is 25 GHz to 32 GHz, and the relative bandwidth is 24.5%. The peak gain is 20.1 dBi. Due to its attractive properties of miniaturization, broadband, and high gain, the proposed antenna array could be applied to millimeter-wave wireless communication systems.
RESUMEN
We experimentally demonstrated a novel and simple scheme to generate D-band millimeter-wave (mm-wave) signal without optical filter based on optical carrier suppression (OCS) and single-sideband (SSB). One intensity modulator (IM) driven by radio frequency (RF) signal at 50 GHz is firstly employed to generate two tones with channel spacing of 2 x RF frequency based on OCS. Another subsequent in-phase/quadrature (I/Q) modulator driven by RF signal at 30 GHz is then applied to generate SSB signal by using independent sideband (ISB). No optical filter is needed so that the whole system can be simplified. After using a D-band photomixer for detection, we finally generated the vector mm-wave at 130 GHz. Based on the proposed system, 4-Gbaud/8-Gbaud quadrature phase shift keying (QPSK) information carried by the generated D-band mm-wave signals were transmitted over 22.5-km single model fiber (SMF) and 1-m wireless distance radio-over-fiber (ROF) link. Bit-error-ratio (BER) performances under hard/soft-decision forward-error-correction (FEC) threshold are shown respectively in cases of two different signals transmission rates.
RESUMEN
This paper presents a novel J band (220-325 GHz) MEMS switch design. The equivalent circuits, the major parameters, capacitance, inductance and resistance in the circuit were extracted and calculated quantitatively to carry out the radio frequency analysis. In addition, the mechanical property of the switch structure is analyzed, and the switching voltage is obtained. With the designed parameters, the MEMS switch is fabricated. The measurement results are in good agreement with simulation results, and the switch is actuated under a voltage of ~30 V. More importantly, the switch has achieved a low insertion loss of ~1.2 dB at 220 GHz and <~4 dB from 220 GHz to 270 GHz in the "UP" state, and isolation of ~16 dB from 220 GHz to 320 GHz in the "DOWN" state. Such switch shows great potential in the integration for terahertz components.
RESUMEN
A novel millimeter-wave synergetic optoelectronic oscillator based on regenerative frequency-dividing oscillation and phase-locking techniques is proposed and experimentally demonstrated. The regenerative frequency-dividing oscillator is embedded for millimeter-wave frequency division, and then synergistically oscillates with the optoelectronic oscillator (OEO) due to injection-locking effect. The phase-locking stabilization technique is skillfully utilized in millimeter-wave OEO via commercial analog phase shifter. As a result, a 40-GHz signal is generated featuring low phase noise, high stability and low spurs. The single-sideband phase noise is about -117 dBc/Hz at 10-kHz offset frequency and the spurious suppression ratio reaches more than 80 dBc. The measured overlapping Allan deviation of the proposed synergetic OEO reaches lower than 10-13 at 1024-s averaging time, which is five orders of magnitude lower than free-running millimeter-wave OEO.
