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 Microwave components Mar 1, 2004 12:00 PM Low-pass, high-pass filters
Mini-Circuits' LFCN low-pass filters and HFCN high-pass filters deliver high rejection outside the passband and virtually eliminate PC-board space demand. A number of models in the DC to 10 GHz range are available with high performance, starting with a tiny 0.12 inch × 0.06 inch hermetically sealed package. The filters have built-in low temperature co-fired ceramic (LTCC) technology for temperature stability, performance repeatability, and high -ower handling capability. Surface-mount directional couplers
RLC Electronics' surface-mount directional couplers simplify installation, while still providing the high directivity and low VSWR of standard couplers. These units are available in both octave and multi-octave bandwidths, over the frequency range of 500 to 3000 MHz. Nominal coupling values of 10 ±0.5 dB, 16 ±0.5 dB, or 20 ±1.0 dB are standard. There are five models in this series with minimum directivity in the 20 to 23 dB range, and maximum loss in the 0.2 to 0.3 dB range. Typical impedance is 50 Ohms and average power rating is 50 W with 3 kW peak. Operating in the -55 to + 85°C, the directional couplers are designed to meet Mil-E-5400 class 1A specs. Diplexer series for RF manufacturing
Pulse, a Technitrol Company, has released a family of scalable modular and robust technology (SMART) diplex filters. The series offers several advantages for worldwide deployment. The components are preset at the factory to the desired frequency, eliminating the end-user's cost of tuning the module in final assembly. The common footprint simplifies board layout for devices that must operate at different frequencies. The filters are suitable for cable modems, set-top boxes, fiber-to-the-premises (FTTP), and hybrid fiber/coax (HFC) equipment. The diplexers feature various frequencies, with or without F-connector, and are available in both lead and lead-free formats. Pulse's lead-free components are designed for countries such as Europe and Japan that have lead-free initiatives. The SMART Diplexer modules are also designed to meet or exceed specifications of applicable regional standards. The diplexers are available in various upstream frequencies ranging from 5 MHz to 65 MHz; and downstream frequencies ranging from 52 MHz to 1200 MHz with different values for crossover isolations and return loss. Latching microwave relay modules
VXI Technology Inc. has launched a suite of latching microwave relay modules, further extending the SMIP The family includes: SM7001L, SM7012L, SM7013L and SM7016L SPDT latching self-terminated 20 GHz relays. The extensive control and interface features of the SMIP EMI filter array
The new KNA21 series from AVX Corporation is a multilayer chip EMI filter array designed to reduce the noise generated from signal lines of digital devices. The device consists of four high-performance EMI filter circuits in a package that measures 2.0 mm × 1.25 mm × 0.85 mm. The product is effective for improving RF reception in mobile phones by minimizing the noise emitted by high-speed digital signals generated by color LCDs and camera functions. The KNA21 series incorporates four EMI filters, managing up to four lines in one component, enabling a reduction in component count, board space and assembly cost. By using dielectric sheets with thinner layers and improved process technology, AVX has made it possible to create smaller, thinner and lighter devices with smaller substrates. The KNA21 EMI filter features a cut-off frequency of 400 MHz and attenuation range of 800 MHz to 2.5 GHz (15 dB attenuation) and 800 MHz to 1 GHz attenuation range (20 dB attenuation), giving it the capability to manage noise attenuation over a broad spectrum in the high frequency range. The filters are rated at 25 VDC and 50 mA. In addition, the EMI filter is compatible with all major digital communications protocols, including CDMA, GSM, PDC, PCS, UMTS and W-CDMA. Additional members of AVX's EMI filter series are the KNF21/32 series for signal lines, the array-type KNA32 series and the KNH21 series for power lines. Typical pricing for the KNA21 series EMI filter is under $0.30 each, in production quantities with lead times from stock to 12 weeks. Chip bandpass filter
Murata Electronics has recently developed a chip multilayer LC band pass filter (LBF32 SM series) for Fixed Wireless Access (FWA) operating in the 26 GHz extremely high-frequency (EHF) band. The filter measures 3.2 mm × 2.5 mm × 1.3 mm, and is surface-mountable with reflow soldering techniques used for conventional, lower- frequency chip components. The use of the Murata's ceramic multilayer construction technique provides features such as a shielding structure and low loss (less than 1 dB insertion loss at points within the passband), and is lead free. GaAs MMIC voltage variable attenuator
Hittite Microwave Corporation has announced a single control, 450-2200 MHz voltage variable attenuator for applications in NMT, cellular, PCS & 3G wireless infrastructure. With up to 48 dB of attenuation range, and +20 dBm of input IP3 throughout its entire attenuation range, the HMC473MS8 is suitable for RF transmit and receive chain applications in virtually all wireless infrastructure applications. The MSOP8 SMT-packaged HMC473MS8 requires no external components and operates from a +3.3 V supply and a single 0 to +3.0 V control voltage. Coaxial switch matrix
Configured as a 1×48 coaxial switch matrix, the 5047 switch from Dow-Key Microwave, a subsidiary of Dover Corporation, performs from DC to 26.5 GHz with Ethernet, GPIB, RS-232, RS-485, and CANbus control interfaces. All unused ports are terminated to 50 ohms internal terminations. Each unit, equipped with a front-panel LCD and keypad for manual override, is housed in a low profile 4U rack-mountable chassis. This CANbus-based switch matrix comes in an enclosure with power supply designed for EMI compliance. The impedance is 50 ohms, and the switching speed is 60 ms. The maximum insertion loss for the unit is 3 dB, while the minimum isolation is rated at 50 dB. The VSWR performance for the switch matrix is 2.0:1. The RF connectors offered by this unit are SMA type. Although this CANbus-based switch matrix is designed for signal routing applications, it can also be used as a building block for numerous ATE applications. PLL-based ASK transmitter
Maxim Integrated Products has introduced the MAX7044, a small VHF/UHF, PLL-based, ASK transmitter with +13 dBm output power that is packaged in a tiny 3 mm × 3 mm, 8-pin SOT23. This transmitter is suitable for low-cost, high-volume applications where space is critical. Examples include key fobs, security products, garage door openers, and remote sensors operating in the 300 MHz to 450 MHz band range. The MAX7044 uses a simple, single-input data interface and a clock-out feature to eliminate the need for an MCU resonator. The device operates from a single Li-ion cell down to 2.1 V and consumes only 100 microamps of current in standby mode. Using an external resistor, the output power can be adjusted from -10 dBm to +13 dBm into a 50-Ohm load. At +13 dBm, the MAX7044 consumes 8.6 microamps of current at 315 MHz, when using a 50% duty-cycle encoding scheme such as Manchester. Current consumption is only 3.7 mA at 0 dBm output, and the device can transmit at date rates up to 100 kbps. Once enabled, the MAX7044 takes only 250 microseconds for the PLL and crystal to settle and be available for transmission. The device accepts crystal frequencies between 10 MHz to 15 MHz, widely available in inexpensive, surface-mount packages. The transmitter's crystal-based PLL eliminates most LC- or SAW-based transmitter problems. The inherent accuracy of the crystal frequency facilitates a narrower IF-bandwidth in the receiver to improve system sensitivity. A sensitivity improvement of 9 dB is possible by narrowing the IF bandwidth from 600 kHz to 50 kHz when the device is used in conjunction with receivers such as Maxim's MAX1470, MAX1473, or MAX7033. Improved sensitivity enables reliable transmissions and an increase in range. The MAX7044 is specified for the -40°C to +125°C automotive temperature range. Prices start at $1.17 (10k-up, FOB USA). An evaluation kit is available to speed designs. Crystal reference samples are available on request. Chipscale FBAR filter
Agilent Technologies Inc. has released tiny filters for integration into GSM RF front-end modules. Because of the small size and thermal performance of Agilent's film bulk acoustic resonators (FBARs), filters can now be incorporated into front-end modules, including transceiver modules. FBAR filters are based on the company's Microcap bonded wafer chipscale technology. GSM transceiver and switch module manufacturers are attempting to reduce thickness from about 1.6 mm today to about 1.0 to 1.2 mm in the future. At 0.3 mm high, Agilent's bumped FBAR Microcap filters should enable this reduction. In addition, with a temperature coefficient of -25 ppm/°C, FBAR filters have only 60% the temperature sensitivity of surface acoustic wave (SAW) filters, making them a suitable choice for modules densely populated with heat sources such as transceivers or power amplifiers. The new Microcap chip scale FBAR filters are shipping in prototype quantities to select module manufacturers. They are expected to ship in volume in Q3 2004. Embedded capacitor laminate
Expanding its Interra family of embedded passive materials, DuPont Electronic Technologies has introduced Interra HK11 planar embedded capacitor laminate. Offering flexibility, this ultra-thin, high dielectric capacitor laminate is aimed at eliminating high-frequency bypass capacitors. It is 14 micron-thick ceramic filled dielectric laminate.
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