Compact Folded Monopole Antenna Excited by a Conductor‐Backed Coplanar Waveguide with Vias

A compact monopole antenna excited by a conductor‐backed coplanar waveguide (CBCPW) is developed for wireless USB dongle applications. The proposed antenna has a compact dimension of 14 mm × 47.4 mm × 3.5 mm, which is suitable for a USB dongle housing. A slotted elliptical patch and a CBCPW with vertical vias are employed to achieve a further size reduction and an improved impedance bandwidth. The measurement result demonstrates that the fabricated antenna resonates from 2.25 GHz to 10.9 GHz, which covers all of the important wireless communication bands, including WiBro (2.3 GHz to 2.4 GHz), Bluetooth (2.4 GHz to 2.484 GHz), WiMAX (2.5 GHz to 2.7 GHz and 3.4 GHz to 3.6 GHz), satellite DMB (2.605 GHz to 2.655 GHz), 802.11b/g/a WLAN (2.4 GHz to 2.485 GHz and 5.15 GHz to 5.825 GHz), and ultra‐wideband (3.1 GHz to 10.6 GHz) services. The radiation characteristics of the proposed antenna when attached to a laptop are tested to investigate the influence of the keypad and the LCD panel of the laptop.     

最大振荡频率为200 GHz的蓝宝石衬底AlGaN/GaN HEMT

本文报道了fmax为200GHz的基于蓝宝石衬底的AlGaN/GaN 高电子迁移率晶体管（HEMT）。外延材料结构采用了InGaN背势垒层来减小短沟道效应,器件采用了凹栅槽和T型栅结合的工艺,实现了Ka波段AlGaN/GaN HEMT。器件饱和电流达到1.1A/mm,跨导为421mS/mm,截止频率（fT）为30GHz,最大振荡频率（fmax）为105GHz。采用了湿法腐蚀工艺将器件的Si3N4钝化层去除后,器件的Cgs和Cgd减小,器件截止频率提高到50GHz,最大振荡频率提高到200GHz。     

（英）一种基于新型自组装微带-波导过渡的D波段通信发射机模块

展示了一种基于新型自组装微带-波导过渡的D波段（110-170GHz）发射机模块。过渡结构的仿真平均插入损耗为0.6 dB,回波损耗于带内基本优于10 dB。基于该过渡结构以及阻性混频器和倍频器芯片,设计了一种D波段发射机模块。该发射机模块工作于110-153 GHz,峰值输出功率于150 GHz可达-4.6 dBm,3-dB带宽为145.8-159.3 GHz。使用该模块进行了64-QAM高阶无线通信测试,测试传输速率为3 Gb/s,验证了模块封装方案的实用性。     

60-GHz CPW-fed post-supported patch antenna using micromachining technology

A 60-GHz coplanar waveguide (CPW)-fed post-supported patch antenna is presented using micromachining technology. In the proposed structure, the radiating patch and the feed line network can be optimized separately with a substrate. The antenna performance is improved by elevating the patch in the air. A patch array antenna is also designed with a simple feed network. The fabricated antenna shows broad band characteristics such as -10 dB bandwidth of 4.3GHz from 58.7GHz to 64.5GHz in the single patch antenna and 8.7GHz from 56.3GHz to 65GHz in 2/spl times/1 patch array antenna.     

A novel Ultra WideBand monopole antenna with band-notched characteristics

A simple and compact microstrip-fed Ultra WideBand(UWB) printed monopole antenna with band-notched characteristic is proposed in this paper.The antenna is composed of a square ring with a small strip bar,so that the antenna occupies about 7.69 GHz bandwidth covering 3.11～10.8 GHz with expected band rejection from 5.12 GHz to 5.87 GHz.A quasi-omnidirectional and quasi-sym-metrical radiation pattern is also obtained.This kind of band-notched UWB antenna requires no ex-ternal filters and thus greatly simplifie...     

G-band (140-220 GHz) and W-band (75-110 GHz) InP DHBT medium power amplifiers

We report common-base medium power amplifiers designed for G-band (140-220 GHz) and W-band (75-110 GHz) in InP mesa double HBT technology. The common-base topology is preferred over common-emitter and common-collector topologies due to its superior high-frequency maximum stable gain (MSG). Base feed inductance and collector emitter overlap capacitance, however, reduce the common-base MSG. A single-sided collector contact reduces C_ce and, hence, improves the MSG. A single-stage common-base tuned amplifier exhibited 7-dB small-signal gain at 176 GHz. This amplifier demonstrated 8.7-dBm output power with 5-dB associated power gain at 172 GHz. A two-stage common-base amplifier exhibited 8.1-dBm output power with 6.3-dB associated power gain at 176 GHz and demonstrated 9.1-dBm saturated output power. Another two-stage common-base amplifier exhibited 11.6-dBm output power with an associated power gain of 4.5 dB at 148 GHz. In the W-band, different designs of single-stage common-base power amplifiers demonstrated saturated output power of 15.1 dBm at 84 GHz and 13.7 dBm at 93 GHz     

Microwave Frequency Division and Multiplication Using an Optically Injected Semiconductor Laser

Nonlinear dynamics of semiconductor lasers is applied for microwave frequency division. Optical injection is used to drive a slave laser into the dynamical period-two state. A fundamental microwave frequency and its subharmonic are generated in the power spectrum. Both frequencies will be simultaneously locked when an external microwave near either frequency is applied on the bias. In our experiment, precise microwave frequency division is demonstrated by modulating the laser at the fundamental of 18.56 GHz. A locked subharmonic at 9.28 GHz with a low phase variance of 0.007$hbox rad^2$is obtained from a 10-dBm input. A large locking range of 0.61 GHz is measured under a 4-dBm modulation. Similarly, precise frequency multiplication is demonstrated by modulating at 9.65 GHz. At an input power of$-$5 dBm, a multiplied signal at 19.30 GHz is obtained with a phase variance of 0.027$hbox rad^2$and a locking range of 0.22 GHz.     

Low profile multiband rectenna for efficient energy harvesting at microwave frequencies

This paper presents the design and development of a multiband rectenna for ambient RF energy harvesting. The proposed rectifying antenna consists of fractal-based geometry to obtain GSM 0.9 GHz (0.8–1.2 GHz), GSM 1.8 GHz (1.6–2.1 GHz), WLAN 2.5 GHz (2.2–2.8 GHz), Wi-MAX 3.5 GHz (3.1–4.0 GHz), WLAN 5.5 GHz (5.3–6.4 GHz) and 7.35 GHz (7.0–7.8 GHz) resonating bands. The designed sensing antenna is low profile, lightweight and small in size with two circularly polarized bands at frequencies 1.8 and 2.5 GHz. In the proposed rectenna, a dual-stage voltage doubler rectifying circuit is utilized for converting surrounding RF signals into DC power. A matching network is connected between the fractal antenna and the rectifying circuitry for realizing a good impedance matching between them. To verify the proposed design, a prototype rectenna is fabricated and measured results are compared with the simulated results. The proposed rectifier provides an RF to DC conversion efficiency of 78%.     

Generation of millimetre and sub-millimetre waves by photomixing in1.55 μm wavelength photodiode

A 70 GHz bandwidth commercial photodiode has been used to create a photomixer source of radiation at frequencies from 70 GHz to above 600 GHz. The waveguide source is driven by two 1.55 μm lasers and delivers a peak, nonsaturated, power of -7.5 dBm at 110 GHz with a power conversion efficiency above 1%. Detected power decreases approximately as 1/(frequency)⁴ above 150 GHz     

3GHz低功耗低相位噪声的带自偏置电流源的LC压控振荡器

利用0.18μm CMOS工艺实现了一个全集成的工作于3GHz的低功耗、低相位噪声的压控振荡器,且带有自偏置电流源.通过对改进的电流源进行优化,在噪声与功耗之间达到了折中.该压控振荡器可工作于2.83至3.25GHz频段内,调谐范围达到13.8%.当工作于3.22GHz时,测得的相位噪声在1MHz频偏处为-111dBc/Hz.在1.8V电源电压下,核心模块消耗电流小于2mA.表明该电路适合5GHz的无线局域网接收机以及3.4至3.6GHz的全球微波互联接入(WiMAX)应用.     

Low-loss and high-selectivity bandpass filter with harmonic suppression and piezoelectric transducer tuning

A low-loss and high-selectivity bandpass filter with harmonic suppression and piezoelectric transducer (PET) tuning is presented. At the 3.5 GHz passband, the insertion loss is 1.48 dB, and the transmission zeros at 3.05 and 4.08 GHz have a rejection of 55 dB. The rejection at the 7 GHz second harmonic is 50 dB. A PET tunes the bandstop sections to obtain a tunable suppression (>45 dB) around the second harmonic from 5.35 to 7.8 GHz.     

W‐Band MMIC chipset in 0.1‐μm mHEMT technology

We developed a 0.1‐μm metamorphic high electron mobility transistor and fabricated a W‐band monolithic microwave integrated circuit chipset with our in‐house technology to verify the performance and usability of the developed technology. The DC characteristics were a drain current density of 747 mA/mm and a maximum transconductance of 1.354 S/mm; the RF characteristics were a cutoff frequency of 210 GHz and a maximum oscillation frequency of 252 GHz. A frequency multiplier was developed to increase the frequency of the input signal. The fabricated multiplier showed high output values (more than 0 dBm) in the 94 GHz–108 GHz band and achieved excellent spurious suppression. A low‐noise amplifier (LNA) with a four‐stage single‐ended architecture using a common‐source stage was also developed. This LNA achieved a gain of 20 dB in a band between 83 GHz and 110 GHz and a noise figure lower than 3.8 dB with a frequency of 94 GHz. A W‐band image‐rejection mixer (IRM) with an external off‐chip coupler was also designed. The IRM provided a conversion gain of 13 dB–17 dB for RF frequencies of 80 GHz–110 GHz and image‐rejection ratios of 17 dB–19 dB for RF frequencies of 93 GHz–100 GHz.     

（英）D波段InP基高增益、低噪声放大芯片的设计与实现

利用90-nm InAlAs/InGaAs/InP HEMT工艺设计实现了两款D波段（110~170 GHz）单片微波集成电路放大器。两款放大器均采用共源结构,布线选取微带线。基于器件A设计的三级放大器A在片测试结果表明：最大小信号增益为11.2 dB@140 GHz,3 dB带宽为16 GHz,芯片面积2.6×1.2 mm2。基于器件B设计的两级放大器B在片测试结果表明：最大小信号增益为15.8 dB@139 GHz,3dB带宽12 GHz,在130~150 GHz频带范围内增益大于10 dB,芯片面积1.7×0.8 mm2,带内最小噪声为4.4 dB、相关增益15 dB@141 GHz,平均噪声系数约为5.2 dB。放大器B具有高的单级增益、相对高的增益面积比以及较好的噪声系数。该放大器芯片的设计实现对于构建D波段接收前端具有借鉴意义。     

Dual mode wideband band-pass filter with notched band for communication system

This paper presents a planar microstrip wideband dual mode Band-Pass Filter (BPF) from 2 GHz to 3.4 GHz with a notched band at 2.62 GHz. The dual mode band-pass filter consists of a ring resonator with two quarter-wavelength open-circuited stubs at ?? =90° and ?? =0°, respectively. A square perturbation stub has been put at the corner of the ring resonator to increase the narrow stopbands and improve the performance of selectivity. By using a parallel-coupled feed line, a narrow notched band is introduced at the required frequency and its Fractional BandWidth (FBW) is about 5%. The proposed filter has a narrow notched band and a wide pass-band with a sharp cutoff frequency characteristic, the attenuation rate for the sharp cutoff frequency responses is 297.17 dB/GHz (calculated from 1.959 GHz with ?34.43 dB to 2.065 GHz with ?2.93 dB) and 228.10 dB/GHz (calculated from 3.395 GHz with ?2.873 dB to 3.507 GHz with ?28.42 dB). This filter has the advantages of good insertion loss in both operating bands and two rejections of greater than 16 dB in the range of 1.59 GHz to 1.99 GHz and 3.49 GHz to 3.98 GHz. Having been presented in this article, the measurement results agree well with the simulation results, which validates our idea.     

（英）一种基于透镜天线的宽带太赫兹准光检波器

设计了一种能够工作在140~325 GHz频带的宽带准光检波器,由一颗高阻硅透镜和单片集成检波芯片组成.设计并加工出双缝天线,在天线馈电端集成了肖特基二极管,该紧凑结构使其能够接收空间中的太赫兹辐射并转换为基带信号.为增强片上天线的方向性,利用MLFMM算法进行了扩展半球硅透镜的设计和优化,实现了良好的辐射特性.通过测试,天线在220 GHz和324 GHz处的辐射增益分别为26 dB和28 dB.在140~325 GHz,检波器测试得到的响应率可达到1 000~4 000 V/W,对应的等效噪声功率(NEP)估算为0.68~273 pW/Hz.     

一种新型平面超宽带天线的设计

提出了一种微带线馈电的新型平面超宽带单极天线。该天线由带有弧边的金属贴片与开槽接地板构成,通过等腰梯形与圆弧形相结合的方式对接地板进行开槽,将其等分为相互耦合的两部分,起到了阻抗匹配与拓宽带宽的效果。仿真结果表明反射损耗在-10 dB以下的频率覆盖范围为3～11.8 GHz,并且在3.4～11.2 GHz频带驻波比在1.5以下,具有良好的全向辐射特性。该天线结构简单,体积小,适合在UWB通信中应用。     

Flat spectral response arrayed-waveguide grating multiplexer withparabolic waveguide horns

An eight-channel flat spectral response arrayed-waveguide grating multiplexer with parabolic waveguide horns has been fabricated on a planar lightwave circuit (PLC). A double-peaked intensity distribution is formed at the slab interface by the parabolic waveguide horn. A 1 dB bandwidth of 98 GHz, 3 dB bandwidth of 124 GHz and 20 dB bandwidth of 196 GHz are obtained for 200 GHz channel spacing. The crosstalk to neighbouring channels is less than -27 dB and the on-chip insertion losses range from 6.1 to 6.4 dB, respectively     

一种新型MEMS可调滤波器的设计

提出了一种采用非均匀分布MEMS结构的可调滤波器设计方案。基于这种新型结构,讨论了一个中心频率为20GHz的二阶带通可调滤波器模型。通过HFSS对该二阶带通滤波器模型进行了全波分析。仿真结果表明:通过分别改变共面波导结构上方不同部分的MEMS电容高度,该滤波器中心频率在18.71~20.62GHz连续可调,相应的3dB带宽值为2.36GHz和2.94GHz。该滤波器9.5%的可调率相比于同类型均匀分布式滤波器的可调范围增加了大约18.6%(300MHz)。通过分析可知,采用非均匀分布MEMS结构的可调滤波器不仅结构更紧凑合理,而且获得了比均匀结构更大的调节范围,极大地增加了设计的灵活性。     

Coplanar millimeter-wave ICs for W-band applications using 0.15μm pseudomorphic MODFETs

A small signal S-parameter and noise model for the cascode MODFET has been validated up to 120 GHz, allowing predictable monolithic microwave integrated circuit (MMIC) design up to W-band. The potential of coplanar waveguide technology to build compact, high performance system modules is demonstrated by means of passive and active MMIC components. The realized passive structures comprise a Wilkinson combiner/divider and a capacitively loaded ultra miniature branch line coupler. For both building blocks, very good agreement between the measured and modeled data is achieved up to 120 GHz. Based on the accurate design database, two versions of compact integrated amplifiers utilizing cascode devices for application in the 90-120 GHz frequency range were designed and fabricated. The MMICs have 26.3 dB and 20 dB gain at 91 GHz and 110 GHz, respectively. A noise figure of 6.4 dB was measured at 110 GHz. The 90-100 GHz amplifier was integrated with an MMIC tunable oscillator resulting in a W-band source delivering more than 6 dBm output power from 94 to 98 GHz     

Microstrip Lowpass Filter with Very SharpTransition Band Using T‐Shaped,Patch, and Stepped Impedance Resonators

A compact microstrip lowpass filter (LPF) with an elliptic function response is proposed. A high equivalent capacitance and inductance between the structures of the resonator result in the sharp transition band of 0.04 GHz from 4 GHz to 4.04 GHz with an attenuation level of ?3 dB and ?20 dB, respectively. To improve the LPF rejection band, multiple open stubs are connected to the proposed resonator. A filter with a 3‐dB cut‐off frequency at 4 GHz is designed, fabricated, and measured, and agreement between the measured and simulated results is achieved. The results show that a stopband bandwidth of 131% with a suppression level better than ?20 dB is obtained while achieving a compact size with a wide stopband.