Single Instrument Generates Precise SNRs
A signal-to-noise generator series called the CNG-EbNo promises to tackle applications requiring high data rates that have to be transmitted reliably under challenging circumstances. Te instruments are designed for carrier-to-noise (C/N), carrier-to-noise density (C/No), signal-to-noise (S/N), carrier-to-interferer (C/I), and bit-energy- to-noise-density (Eb/No) analysis. Te CNG-EbNo generators are available in custom as well as off-the-shelf frequency bands.
To name just a few standard versions, for example, the CNG-EbNo-5 covers 1 to 10 MHz while the CNG-EbNo-IBS/ IDR spans 50 to 90 MHz, 68 to 72 MHz, and 100 to 180 MHz. The generators are suitable for satellite-communications testing, cable-television and high-definition television testing, and measurements in various cellular bands, wireless local-area networks (WLANs), and WiMAX systems. Among the telecommunications bands targeted are 650 to 850 MHz with the CNG-EbNo-750, 800 to 1000 MHz with the CNGEbNo- 900, and 1900 to 2200 MHz with the CNG-EbNo-2050. An internal power meter promises to provide repeatable signal-to-noise ratio (SNR) waveforms for accurate signal generation.
The instruments are available in 50- or 75-O impedance versions. They offer a signal input range of -55 to +5 dBm. For the carrier path, the instruments provide nominal gain of 1.0 dB with gain resolution of 0.1 dB and flatness from 0.2 dB. They exhibit group delay of less than 200 ps. An optional tracking feature stabilizes unstable input signals, which may have level shifts of +4 to -4 dB. That tracker updates at a rate of 100 ms. The signal-to-noise generators flaunt ratio accuracy beyond 0.2 dB root sum of squares (RSS) and 0.3 dB WCU. During bit energy-to-noise density analysis, the CNG-EbNo analyzers automatically calculate noise density based on user-specified bit rates, which can range from 1 b/s to 999 Mb/s. A touchscreen display promises to ease the setting of all measurements.
Wireless Telecom Group, Inc., 25 Eastmans Rd., Parsippany, NJ 07054; (973) 386-9696, FAX: (973) 386-9191, www.wtcom.com.
Analysis Software Simplifies Linearization Of Active Components
With a spectrum analyzer, signal generator, and personal computer (PC), the R&S FS K130 distortionanalysis software allows users to both characterize and linearize amplifiers quickly and easily. Te software even compensates for the memory effects exhibited by many amplifiers. Te setup measures the amplifier's characteristics and calculates the correction required to attain a linear output signal. Te application, which runs on Windows XP, was designed for a test setup based on the R&S FSV or FSQ spectrum analyzers as well as the R&S SMBV or SMU200A signal generators. Te software controls the instruments and characterizes the amplifier using the same signal waveform that will be driving the amplifier.
For its part, the spectrum analyzer captures and records the amplifier's output signal. The software uses this information to calculate a model that describes the signal's characteristics, such as amplifier distortion. Based on the calculated amplifier model, the software determines a corresponding model that is used to predistort the input signal, thereby improving both the error vector magnitude (EVM) and adjacent-channel leakage ratio (ACLR). The R&S FS-K130 distortion analysis software offers various mathematical simulation models, such as the Volterra series and a simpler polynomial expression to model amplifier behavior. With an easy-to-use, block-diagram-based user interface, the analysis solution delivers AM/AM and AM/FM conversion curves showing amplitude compression and phase change versus input power.
Reference and test signals can be displayed versus time or as a spectrum, probability distribution function (PDF), or complementary cumulative distribution function (CCDF). The amplifier and predistortion models can be exported in Matlab format (MAT). Measured values are saved in common graphic file formats and CSV files.
Rohde & Schwarz, Mhldorfstrae 15, 81671 Mnchen, Germany; +49 89 41 29 0, FAX: +49 89 41 29 12 164, www.rohde-schwarz.com.
GPS LNAs Provide 0.65 dB Noise In 1 mm2
To extend receiver sensitivity and read range, two new additions to a Global Positioning System (GPS)/global navigation satellite system (GNSS) low-noiseamplifier (LNA) family flaunt a noise figure of 0.65 dB for GPS L1 frequencies from 1563 to 1588 MHz and GNSS frequencies from 1592 to 1615 MHz. Te MAX2667/MAX2669 provide different linearity options to suit system requirements. To ensure superior receive performance in the presence of signal blockers, for example, the MAX2669 (at -4.5 dBm) provides an input-thirdorder- intercept point that is approximately 8 dB better in band and out of band than the MAX2667 (at -3.5 dBm). Te result is a mere 4.0-mA extra supply current. With a typical operating supply current of 4 mA, the MAX2667 also provides extended battery life. When they are not in use, both LNAs have an optional logic-enabled shutdown mode that reduces supply current to less than 1 mA. Te amplifiers are offered in a 0.4-mm-pitch wafer-level package (WLP), which occupies 1 mm2 of board space. Te MAX2667/MAX2669 operate from a 1.6-to-3.3-V supply over -40 to +85C. P&A: Starting at $0.54 in 1000Q.
Maxim Integrated Products, Inc., 120 San Gabriel Dr., Sunnyvale, CA 94086; (408) 737-7600, FAX: (408) 470-5841, www.maxim-ic.com.
VCO Spans 172 To 210 MHz
To serve transmitter applications, a new family of voltage-controlled oscillators (VCOs) features an extra transmit modulation port. The CVCO55FLM VCOs boast a modulation port with a negative slope and typical modulation sensitivity of -20 kHz/V. The CVCO- 55FLM-0172-0210, for example, operates from 172 to 210 MHz with a control voltage range of 0.2 ~ 4.8 V. Typically, it provides phase noise of -119 dBc/Hz at 10 kHz off set from the carrier. With typical output power of 0 dBm, the CVCO55FLM-0172-0210 requires +3 VDC voltage while consuming maximum current of 9 mA. The VCO minimizes pulling and pushing to 1.0 MHz and 0.5 MHz/V, respectively. It generally off ers second-harmonic suppression of -20 dBc. The model CVCO- 55FLM-0172-0210 is housed in a 0.5-x-0.5-in. SMD package.
Crystek Corp., 12730 Commonwealth Dr., Ft. Myers, FL 33913; (239) 561-3311, FAX: (239) 561-1025, www.crystek.com.
Detector Simultaneously Reads RMS And Envelope Power
In addition to being a root-mean-square (RMS) detector, the ADL5511 can measure an RF input signal's envelope power. Operating from 1 MHz to 4 GHz, the ADL5511 TruPwr RMS and envelope detector boasts 0.25 dB RMS-detection and envelopedetection accuracy versus temperature. The device fl aunts a 1-dB dynamic range of 40 dB. It off ers a 100-MHz envelope bandwidth while keeping envelope delay below 5 ns. Essentially, the ADL5511 presents the envelope output as a voltage that is proportional to the envelope of the input signal. It has a conversion gain of 1.4 V/V and is referenced to an internal 1.1-V reference voltage, which is available on the EREF pin. The RMS output is a linear-in-V/V output voltage, which is independent of the peak-to-average ratio of the input signal. It provides conversion gain of 1.8 V/V RMS at 900 MHz.The extracted envelope can be used for power-amplifi er (PA) linearization and effi ciency enhancements while the RMS output can be used for true power measurement. The ADL5511 targets wireless, instrumentation, defense, and broadband applications. It is especially well suited for the envelope detection of broadband, high peak-to-average signals, such as CDMA2000, W-CDMA, LTE, and QPSK/QAM-based orthogonal-frequency-division-multiplexing (OFDM) waveforms. The ADL5511 operates from 40 to +125C. P&A: sampling; $7.33 per unit in 1000Q.
Analog Devices, One Technology Way, P.O. Box 9106, Norwood, MA 02062-9106; (781) 329-4700, FAX: (781) 461-3113, www.analog.com.