CNG-EbNo Series Precision SNR Generator
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Count on the noise leader Data Sheet CNG-EbNo Series Precision SNR Generator

2 CNG-EbNo Series Precision SNR Generators The CNG-EbNo is a fully automated instrument that sets and maintains a highly accurate ratio between a user-supplied carrier and internally generated noise, over a wide range of signal power levels and frequencies. The CNG-EbNo gives system, design, and test engineers in the cellular/PCS, satellite and military communication industries a cost-effective means of obtaining higher yield through automated testing, plus increased confidence from repeatable, accurate test results. Features Multiple Operating Modes The CNG-EbNo provides five operating...

3 Eb/No – The instrument automatically sets up a desired Eb/ No quickly and accurately. Based on the user-specified carrier output level, output Eb/No ratio, and bit rate, the instrument automatically calculates the required noise density. C/N – This mode sets the specified carrier output level and the total noise power in the system bandwidth to the desired ratio. C/No – To obtain a specific C/No ratio, set the instrument to Eb/ No mode and enter zero for the bit rate. All other functions are the same as the Eb/No mode. C/I – This mode sets the specified carrier output level and the user...

4 Carrier to Noise Ratio (C/N) What is it? C/N is the ratio of the relative power level to the noise level in the bandwidth of a system. Why we need it? Allows to analyze if a carrier can still be recognized as such, or if it is obliterated by ambient and system noise. C/N Provides a value for the quality of a communication channel. How to measure? The quality of the system is usually determined through BER plots against C/N. Noise Spectral Density (No) What is No? Noise spectral density (No) is defined as the amount of (white) noise energy per bandwidth unit (Hz). No = N / B No is often...

5 Carrier to Noise Density Ratio (C/ No) What is it? C/No is the ratio of the power level to the noise power spectral density (normalized noise level relative to 1 Hz) in a system. Why we need it? Similar as C/N but C/No does not factor the actual noise bandwidth in. This simplifies analysis of systems where variation of the (utilized) BW may apply. How to measure? As C/N, C/No is usually determined through BER plots Energy per bit (Eb) What is Eb? Energy per information bit (i.e. the energy per bit net of FEC overhead bits). Carrier power divided by actual information bits. Eb = C/R Where...

6 Performance of BER vs Eb/No This block diagram shows an example of typical satellite modem loop test set up from where it is possible to find the ideal performance of BER vs Eb/No. The CNG-EbNo tester sets up the Eb/No and a standard BER test equipment measures the bit error rate. Plotting BER vs. Eb/No produces a waterfall like curve to its shape when plotted in a logarithm graph. Eb/No is commonly used with modulation and coding designed for noise-limited rather than interference-limited communication systems, and for power-limited rather than bandwidthlimited communication systems....

7 Specifications Operating modes Carrier-to-noise (C/N), carrier-to-noise density (C/No), bit energyto- noise density (Eb/No), carrier-to-interferer (C/I), noise generator, power meter Carrier Path Input power range -55 dBm to +5 dBm Maximum input power +21 dBm (with no damage) Output power range -55 dBm to +5 dBm Nominal gain ±1.0 dB Gain resolution 0 to -60 dB in 0.1 dB steps Gain flatness ±0.2 dB for 70 MHz ±20 MHz ±0.3 dB for 140 MHz ±40 MHz ±0.4 dB for others Group delay ±0.20 ns/40 MHz for frequencies above 20 MHz Third-order intercept point +29 dBm typical Tracking range (Ubopt01) +4...

Ordering Information Model Number Frequency Range Applications CNG-EbNo-5 1 to 10 MHz Baseband CNG-EbNo-45 5 to 90 MHz General Purpose CNG-EbNo-70 50 to 90 MHz General purpose/SATCOM CNG-EbNo-IF1 50 to 90 MHz Intelsat, SATCOM 100 to 180 MHz CNG-EbNo-IBS/IDR 50 to 90 MHz Intelsat, SATCOM 68 to 72 MHz 100 to 180 MHz CNG-EbNo-225 50 to 400 MHz General Purpose CNG-EbNo-255 240 to 270 MHz SATCOM CNG-EbNo-370 350 to 390 MHz NASA TDRSS CNG-EbNo-CATV 50 to 860 MHz Cable TV, HDTV CNG-EbNo-900 800 to 1000 MHz Cellular CNG-EbNo-750 650 to 850 MHz Iridium, LTE CNG-EbNo-892 822 to 962 MHz Cellular...