SCIENTIFIC Devices Aust Pty Ltd ’s dBm Carrier to Noise Generator series from dBm is a complete line of fully automated carrier to noise generators that sets and maintains a highly accurate ratio between a user-supplied carrier and internally generated white Gaussian noise.
The instruments operate over a wide range of power levels and are compatible with both digital and analog modulation formats. The modular design of the CNG provides one or two totally independent RF channels to allow simplex, diversity or duplex testing.
Precise carrier-to-noise (C/N) or carrier to interference (C/I) ratios may be programmed and the CNG will measure the carrier signal and accurately adjust the power of the internal AWGN source to maintain the desired ratio. The models are available for Cellular, PCS, CATV and SATCOM test applications.
The CNG gives system, design, and test engineers in the wireless communications industry a cost effective means of obtaining higher yields through automated testing, plus increased confidence from repeatable accurate test results. Solid state components ensure high reliability, test speed and durability. And by using the substitution method, errors due to power measurement linearity are eliminated.
The CNG series meets or exceeds the requirements of wireless equipment testing standards that require noise and interference emulation. The CNG has the capability to allow users the option to input interference signals.
The instrument will measure carrier power, noise power and interference power and will accurately set carrier-to-noise (C/N) and carrier-to-interference (C/I) ratios. The instrument is available in a variety of configurations to meet specific testing needs.
Applications include the interference conditions required by all second and third generation cellular and PCS standards. In addition specific models are available for L-band, Sband and IF (70MHz and 140MHz) modem testing.
An extremely stable AWGN source, utilising the noise of a thermal termination avoids the typical amplitude distortion errors found in noise diode implementations. This innovative design coupled with the use of an extremely precise power meter optimised for measuring high crest factor noise signals, assures excellent accuracy and repeatability in setting ratios.