band merged into one, and the impedance bandwidth increased. The existence of the shortest arm of a C-shaped stub-1 (L st2 ) and a stub-2 (L st3 ) caused the highest resonant frequency to decrease and the impedance bandwidth to increase, as shown in Figure 2(c). Therefore, the impedance matching of the proposed antenna can be independently controlled for each frequency band. The antenna was designed and analyzed using the Ansoft High-Frequency Structure Simulator (HFSS V11) [8] and the optimal design parameters discovered were L ¼ L st1 ¼ 16 mm, L st2 ¼ 7 mm, and L st3 ¼ 6 mm.
RESULTSABSTRACT: This article presents an eight-phase divide-by-4 silicon-germanium (SiGe) heterojunction bipolar transistor (HBT) injection-locked frequency divider (ILFD). The ILFD is based on a four-stage ring oscillator and was fabricated in the 0.35 lm SiGe 3P3M BiCMOS technology. The divide-by-4 function is performed by injecting a signal to the base of the tail HBT. At the supply voltage V dd of 1.3 V and at the incident power of 0 dBm, the locking range is about 2.55 GHz from the incident frequency 12.7 to 15.25 GHz. The die area is 0.54 Â 0.54 mm 2 .ABSTRACT: Dual-wavelength clock recovery (CR) based on Stimulated Brillouin Scattering is realized. The maximum frequency spacing of two channels is theoretically analyzed and experimentally demonstrated. The total wavelength span of the CR scheme is investigated to be about 3.37 nm in experiment. Multiwavelength CR can be implemented within the span.