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(一)声表面波技术 190 800MHz移动式电话收发两用机用低损耗离性能SAW滤波器——(Kinoshita Y.)《IEEE Trans.Veh.Technol.》VT-32 3(19B8)225—9 研制成移动式电话收发两用机的射频电路用的低损耗高性能SAW滤波器获得了两种性能优良的UHF(800MHz)和VHF(90MHz)带通滤波器在大量生产UHF/VHF集成电路中用SAW滤波器有较大的优越性。(声)     

电路仿真业务处理器

鼎芯半导体（Comlent）开发了用于PHS/PAS（小灵通）手机终端的RFIC收发器和功率放大器芯片组，PHS/PAS射频收发器芯片CL3110和功放CL3503芯片满足并超越RCR STD-28国际标准的要求，灵敏度高，可以帮助增加网络覆盖。射频收发器CL3110采用低中频（10.8MHz）的架构，内置VCO和小数分频PLL，无须外置SAW滤波器。CL3110和CL3503采用0.35um的Bi-CMOS工艺，     

基于HCT-FEM和3D电磁模型的SAW滤波器性能仿真系统

该文基于分层级联有限元(HCT-FEM)和三维电磁模型构建了一套声表面波(SAW)滤波器性能仿真系统。采用Matlab协同COMSOL建立的HCT-FEM模型计算声学元件导纳,用ANSYS建立的三维电磁模型计算含芯片走线、引线/金属球、封装外壳及测试电路的外部电磁S参数,并在ADS软件中对SAW滤波器频率响应进行复原。将该系统应用于一款芯片级封装(CSP)的普通SAW滤波器和一款表贴封装(SMD)的单晶薄膜SAW滤波器电性能仿真,仿真与实测结果吻合较好。     

简讯

Sawtek公司推出移动电话用 K-PCSSAW滤波器Sawtek公司的这种手机用 K- PCS RF SAW滤波器具有相当低的插损 ,其采用的是 2 mm× 2 m m的倒装片外壳。滤波器(85 6 0 82 )中心频率为 176 5 .0 MHz,带宽为 30 MHz,插损为 2 .7d B(最大 )。另一种滤波器 (85 6 0 83)中心频率为 185 5 .0 MHz,带宽为 30 MHz,插损为 2 .5 d B(最大 )。村田公司的 RF SAW滤波器体积仅为 2 .5× 2× 1(mm3)日本村田推出了世界上最小的用于 W- CDMA 的 RF SAW滤波器 ,两种滤波器 (SAFSE1G95 KBOTOO 和SAFSE2 G14 KBOTOO型 )的最大尺寸为 2 …     

用于GPS CDMA电话的射频SAW滤波器

日本 Kyocera公司已开始批量生产该公司两种射频 SAW滤波器的一种 ,型号为 SF38- 1 575T,主要用于具有 GPS功能的移动电话。SF38- 1 575型滤波器外形尺寸为 3.80 mm× 3.80 mm× 1 .2 mm,质量 0 .0 5g,质量和体积分别减少了 75%和 80 %。据称 ,这种滤波器集成了两种滤波器的功能——介质前端滤波器和SAW中级滤波器 ,前端和中级滤波器具有 40 d B或更好的绝缘性。前端滤波器的插损为 0 .9d B,中级滤波器具有 30 d B甚至更好的衰减。公司计划在今年四月将产量增加到 2百万用于GPS CDMA电话的射频SAW滤波器@刘荣贵…     

低损耗、髙矩形度声表滤波器设计研究

针对高矩形度低损耗声表面波(SAW)滤波器的需求背景,对混合结构低损耗SAW滤波器的设计技术展开研究,通过建立混合结构滤波器模型,分析优化滤波器性能,成功研制出中心频率260 MHz,插入损耗为2dB,矩形系数优化1.6的声表滤波器,测试与仿真结果基本一致。     

国外简讯

为了满足小型便携电话、传呼机、无绳电话以及其它移动通讯设备的需求,用于这些设备的SAW器件体积越来越小.目前,日本最小的HT—9000便携电话体积仅110cm~3,重190g.这种超小型便携电话使用4个TQS—737型射频SAW滤波器.用于便携式电话80～100MHz频段的SS一13072型中频SAW滤波器的大小为13mm×7mm×2mm.用于传呼机250～500MHz频段的SS—972型大小为9mm×7mmc2mm,用于便携和无绳塞电话800～1000MHz频段的SS—541射频SAW滤波器的大小仅为5mm×4mm×1mm.这些型号的SAW滤波器都是表面装配式,不但小而轻,而且高度可靠,完全能承受再流焊.     

小型化双通带声表滤波器设计研究

针对小型化双通带声表面波(SAW)滤波器的需求背景,对两端口、两通带的SAW滤波器的设计技术展开研究。通过搭建包含两组耦合模（COM）参数的双通带SAW滤波器声电协同仿真平台,分析优化滤波器性能,成功研制出CSP2520封装的双通带SAW滤波器，其中心频率分别为1 995 MHz和2 185 MHz，通带带宽均为40 MHz，插入损耗小于3 dB，通带间隔离度大于30 dB。测试与仿真结果基本一致。     

简析CDMA对GSM网的干扰

中国联通的CDMA和GSM基站的频谱分配如图1所示。由图1可知，中国联通的CDMA系统基站的发射频率为870—880MHz，接收频率为825-835MHz；GSM的接收频段为890-908MHz（中国移动）和909-915MHz（中国联通），发射频段为935-953MHz（中国移动）和954-960MHz（中国联通）。从运行频段上看，CDMA的发射频段与GSM的接收频段比较接近，因此在站址选择及网络规划中如稍不恰当，势必造成对GSM的干扰，致使GSM系统接收性能下降（注：干扰是相互的，但由于GSM的发射频段与CDMA的接收频段相差较远，且CDMA是自扩频通信系统，抗干扰性能较好，故GSM对CDMA系统造成的干扰可以忽略）。CDMA系统设备一般在基站射频输出端有一宽带滤波器，滤波器的通带为869-894MHz，通带外的衰减一般为20dB。即使CDMA射频发射端采用宽带滤波器，当GSM与CDMA网站距离较近时，仍会对GSM系统产生杂散干扰，甚至导致GSM宽带接收机趋向饱和而无法正常工作。因此需要采取必要的措施，以减少GSM系统受杂散发射干扰的影响。     

可调的声表面波(SAW)滤波器

最近 ,美国新泽西州 Rutgers大学的朱家华 ( Jianhun Zhu)等人研制出一种可调的声表面波 ( SAW)滤波器。这种器件由表面波传播通道中并联的 1 1个叉指换能器组成。通过选择或组合不同的叉指换能器来实现不同的 SAW滤波器结构 ,从而达到其中心频率和 3d B带宽这二者的可调性。例如 ,通过 RF开关 ,可使SAW滤波器的中心频率达到 1 2 6.8～ 1 99.1 MHz,而其 3d B带宽范围可从 1 8.8～ 58.9MHz。这种可调的 SAW滤波器 ( TSF)可以在自适通讯和雷达系统中获得广泛的应用。在扩频通讯系统中 ,可调 SAW滤波器能够起消除干扰的前置滤波器…     

Miniaturized SAW devices for radio communication transceivers

Various applications of surface-acoustic-wave (SAW) technologies are investigated in which the use of SAW devices would result in reduced volume and weight for VHF/UHF radio communication transceivers. Attention is given to improved insertion loss and power requirements reported for SAW filters. In particular, by analyzing the loss mechanisms of a previously developed high-performance SAW filter for mobile telephones, a new extremely low-loss SAW filter (loss of as low as 1.2-2.0 dB at 600 MHz) has been developed. The results of fundamental experiments for a SAW antenna duplexer using this new SAW filter as the transmitter filter with a semicoaxial filter as the receiver filter at 800 MHz are presented     

Low loss and high performance SAW filters for 800 MHz mobile telephone transceiver

Low loss surface acoustic wave (SAW) filters have been developed for use in the radio frequency circuits of the mobile telephone transceiver. Both the UHF (800 MHz) and VHF (90 MHz) band-pass filters have exhibited high performance, and the employment of the SAW filters has shown advantages in UHF/VHF circuit integration for mass production.     

Applications of surface acoustic and shallow bulk acoustic wavedevices

Surface acoustic wave (SAW) device coverage includes delay lines and filters operating at selected frequencies in the range from about 10 MHz to 11 GHz; modeling with single-crystal piezoelectrics and layered structures; resonators and low-loss filters; comb filters and multiplexers; antenna duplexers; harmonic devices; chirp filters for pulse compression; coding with fixed and programmable transversal filters; Barker and quadraphase coding; adaptive filters; acoustic and acoustoelectric convolvers and correlators for radar, spread spectrum, and packet radio; acoustooptic processors for Bragg modulation and spectrum analysis; real-time Fourier-transform and cepstrum processors for radar and sonar; compressive receivers; Nyquist filters for microwave digital radio; clock-recovery filters for fiber communications; fixed-, tunable-, and multimode oscillators and frequency synthesizers; acoustic charge transport (ACT); and other SAW devices for signal processing on gallium arsenide. Shallow bulk acoustic wave (SBAW) device applications include gigahertz delay lines, surface-transverse-wave resonators employing energy-trapping gratings and oscillators with enhanced performance and capability     

声表面波低损耗滤波器的进展

本文从分析获得声表面波低损耗的途径出发,概述声表面波低损耗滤波器的最新进展,介绍几种单层工艺制作的实用型声表面波低损耗滤波器结构。并报道我们研究的650MHz高频低损耗滤波器以及10%宽带低损耗滤波器的结果。     

A High Dynamic Range Programmable CMOS Front-End Filter with a Tuning Range from 1850 to 2400 MHz

This paper presents a highly programmable front-end filter and amplifier intended to replace SAW filters and low noise amplifiers (LNA) in multi-mode direct conversion radio receivers. The filter has a 42 MHz bandwidth, is tunable from 1850 to 2400 MHz, achieves a 5.8 dB NF, –25 dBm in-band 1-dB input compression point (ICP) and 0 dBm out-of-band ICP while drawing 26 mA from a 2.5 V supply.     

250 MHz SAW FILTERS FOR SS/FDMA SYSTEM EMPLOYING ST-CUT QUARTZ SUBSTRATES

Surface acoustic wave (SAW) filters are key devices in developing the bandwidth-variable filter matrix for the subchannel switched frequency division multiple access (SS/FDMA) system. This paper addresses the design and fabrication of two 250 MHz SAW filters employing temperature-stable ST-cut quartz substrates. The specafications for these filters are decided with due consideration of practical use by INTELSAT-type satellites. Measured electrical responses of the individual and combined channels show satisfactory performance. Computer simulations are performed using the measured responses to assess the effects of the SAW filters on digital carriers. Finally, the effects of the temperature and ageing stability characteristics are discussed based on the measured and calculated responses.     

数字无绳电话用声表面波滤波器

简要介绍了四川压电与声光技术研究所研制的数字无绳电话用声表面波滤波器,包括110．592MHz中频滤波器和900MHz系列射频滤波器。中频滤波器的插入损耗为3．5dB,射频滤波器的插入损耗为2．5－3dB。     

高频低损耗声表面波滤波器研制

回顾了低损耗声表面波滤波器的主要设计方法，介绍了镜像阻抗连接换能器结构中调整滤波器带宽的设计技术，给出了在９６０ＭＨｚ高频下的两种试验结果，相对带宽分别为１％和２％，插入损耗小于５ｄＢ，阻带抑制优于５０ｄＢ。     

Spurious response sensitivity of two-way transceivers related to the 3rd-order nonlinearity of SAW filters

The spurious response sensitivities (SRSs) of two-way radio transceivers, as determined from the 3rd-order nonlinearities of SAW filters, are compared using two types of filter, the IIDT-type and a newly-developed SAW-resonator-coupled type, in high-power ( approximately 1 W) applications. The latter type is shown to result in an SRS which satisfies system specifications with sufficient margins.<>