A completely asymmetrical dual-band micro-strip filter combined with a complementary split ring resonator (CSRR) consisting of a circle and a square, and substrate integrated waveguide (SIW) is presented in this paper. The proposed design can be applied in the Industrial Scientific Medical (ISM) band. The CSRR of this completely asymmetrical filter, which has both square and circular parts, can realize two distinct passbands and shows higher out-of -band rejection than symmetrical filters; it is an asymmetrical complementary split ring resonator (ACSRR). The out-of-band rejection level between two passbands can reach 40 dB, compared to 35 dB in a circular filter and 30 dB in a square filter. The measured results are in good agreement with simulated results.
In this letter, a new circuit structure for CMOS active polyphase filter is proposed and analyzed. In the proposed structure, the currents produced from two cascode stage with a capacitor and single cascode stage in a single-stage are used to realize high-pass and low-pass functions, respectively. Compared to other conventional active polyphase filters, the proposed polyphase filter uses a simpler structure to achieve strong image rejection at the higher frequency while obtaining lower power consumption and smaller chip area. In the 0.18-μm CMOS process, the proposed active polyphase filter occupies less than 0.36mm2 of chip area. From the measurements, the four-stage active polyphase filter shows an image rejection ratio of more than 58.2dB at frequencies of 26MHz to 65MHz, a voltage gain of 5.8dB and an IIP3 of 1.5dBm at 45 MHz while consuming only 2.64mA from a 1.8-V supply.
We present a method for generating cascaded forward Brillouin scattering (CFBS) on the basis of a counter-propagated pump-probe technique with backward stimulated Brillouin scattering used as its seed. The CFBS, induced by forward stimulated Brillouin scattering (FSBS), is generated via the energy transfer from the probe light to other acoustic resonance frequencies. The CFBS spectrum generated in a 390-m-long highly nonlinear fiber exhibits a high signal-to-noise ratio (SNR), and the center frequencies of its acoustic resonance peaks agree with theoretical values. In addition, the SNR dependence on pump/probe powers and the CFBS frequency shift dependence on temperature are investigated.
This letter presents a D-band wideband power amplifier (PA) in a 65-nm CMOS process. By pole-tuning technique with T-type network, the PA achieves a flat gain response over a wide bandwidth. The high output power is achieved by combining the output power of two PA cells using a Y-type power combiner (YPC). The fabricated prototype achieves a peak gain of 11.5dB at 115GHz with a 3-dB bandwidth of more than 21GHz and a fractional bandwidth of larger than 17.5%. At the operating frequency of 120 GHz, the saturation output power and the output P1dB are 13dBm and 8.7dBm, respectively. The chip occupies a small silicon area of 0.59mm2 including all testing pads with a core size of only 0.32mm2.
An ultra-low-power 5GHz front end with feedforward body bias LNA and single to double balance subharmonic mixer topology for direct conversion receiver is presented. The proposed front end shows higher conversion gain and better noise figure than the conventional front end with subharmonic passive mixer architecture and in the meanwhile retains the advantage of the conventional such as low DC offset and low flicker noise. The measured result demonstrates that the proposed front end can achieve 28.5dB conversion gain, 3.8dB average noise figure, 100KHz flicker noise corner, and -20.5dBm the input-referred third-order intercept point. 2LO-to-RF isolation is -60dB, LO-to-RF is -90dB, 2LO-to-IF is -50dB, LO-to-IF is -70dB. The power consumption is 1mW with 0.6V supply voltage. The chip area is 0.5×0.53mm2.
This study investigates a polarization-diversity Mach-Zehnder delay interferometer (MZDI) for optical signal processing integrated with a polarization beam splitter (PBS) using silicon photonics technology. The PBS consists of two-stage MZDIs. By using the birefringence of the silicon waveguide and controlling the phase with thermal heaters on MZDIs, the polarization extinction ratio (PER) of the PBS was improved. MZDIs with a free spectral range (FSR) of 40 GHz in both TE and TM modes were designed using the group index for both polarization modes. The PER of 40-GHz-FSR MZDIs for TE and TM modes of 15 and 10 dB, respectively, within the C-band were observed.
This paper presents a compact dual-polarized dual-band stacked patch antenna suitable for WLAN. The dual polarization characteristic is achieved by using a cross-slot coupling feed. The designed antenna can operate in the high frequency band (5GHz) by using a circular patch. Under the combined action of the circular patch, a narrow annular parasitic patch and a special barrel-shaped metal platform with the slotted sidewall, a good impedance matching in the low frequency band (2.45GHz) is obtained. The metal platform not only serves as a reflector of the antenna, but also plays a key part in obtaining good impedance matching of the antenna at low frequency. The measured results demonstrate that the operating frequency of the antenna is 2.25-2.8GHz (VSWR<2.0) at low frequency band and 5.02-6.0GHz (VSWR<2.0) at high frequency band. Moreover, a stable radiation pattern is obtained.