micronetics / 26 hampshire drive / hudson, nh 03051 / tel: 603-883-2900 / fax: 603-882-8987 web: www.micronetics.com d d escription escription micronetics line of fullband noise sources are specially designed for built- in test and calibration where there is significant path loss between the noise source and the device. this family of high output fullband noise sources with their compact size are spe- cially designed for ease of integration into microwave systems. with their rugged and stable design, the heart of these noise sources is a small chip and wire hermetic noise module. this is embedded in the housing with a precision launch to the coaxial jack. this design gives is much more stable and rugged than traditional coaxial noise sources which rely on pill pack- aged diodes and beryllium copper bel- low assemblies which are not only are less reliable, but use hazardous materi- als. c c onfigurable onfigurable t t o o your your requirements requirements micronetics fullband noise sources are based on a coaxial design as the base part. as standard options, noise sources can be ordered with either ? coaxial isolator ? waveguide output ? waveguide isolator s s pecifica pecifica tions tions - operating temp: -40 to +85 o c - storage temp: -65 to +125 o c - supply voltage: +15v +/- 1.5v - current draw: @ 200 ma (max) - output impedance: 50 ohm - peak factor: 5:1 rf output model frequency excess noise flatness ratio (db) rfn55l 1.0 to 2.0 ghz 55(min) 2.0 db p-p rfn55s 2.0 to 4.0 ghz 55(min) 2.0 db p-p rfn55c 4.0 to 8.0 ghz 55(min) 2.0 db p-p RFN55C1 3.95 to 5.85 ghz 55(min) 2.0 db p-p rfn55c2 5.85 to 8.20 ghz 55(min) 2.0 db p-p rfn55x 8.0 to 12.4 ghz 55(min) 4.0 db p-p w w a a veguide veguide c c hart hart model frequency w a v eguide RFN55C1 3.95 to 5.85ghz wr-187 rfn55c2 5.85 to 8.20ghz wr-137 rfn55x 8.20 to 12.4ghz wr-90 c c ommon ommon a a pplica pplica tions tions radar built-in test/calibration; where there is significant path loss between the noise source and the receiver. for example, a 30db coupler can be used to feed the test noise signal into the receiver which minimized noise figure while still allowing 25 db enr. jamming systems; these high output devices, when used in conjunction with power amplifiers, offer an efficient means to jam rf/microwave signals. antennal calibration; high output noise can be used for antenna calibration to counter the effects of over-the-air transmission loss. f ullband h igh enr m icrowave n oise s ources s, c and x b ands 6.2008 f ullband o utput c haracteristics f or u se in s ystems
h h ow ow t t o o o o rder rder r f n 5 5 x - x model l = l band * s = s band * c = c band c1 = c band c2 = c band x = x band option 0 = plain 1 = coax isolator 2 = waveguide 3 = waveguide isolator there are several primary uses for employing a noise signal for built-in- test. 1. using noise for built in test:: these high output moduels are ideal for buidl-in-test wehrer there is a significant path loss between the noise source and the point at which the noise signal is used. for an example an 8-way splitter in an array antenna receiver will allow enough power at the receiver plane at each of the eight receive paths. another example allows a high directivity coupler to be used (i.e., 30 db) allowing better receiver noise figure. 2. noise temperature (noise figure) or sensitivity testing: this test uses the noise source to supply a known excess noise ratio (enr) to a device under test for a y-factor measurement. by taking two receiver readings, one with the noise on and one with it off, y-factor can be deter- mined. by knowing the enr and y-factor, one can calculate noise tem- perature (figure) or sensitivity. 3. frequency response: the noise source being broadband can be used as a replacement of a swept source to calculate frequency response of a receiver or other device. by putting in a known spectral signal at the input and taking a reading at the output, one can determine the gain or loss over frequency of the entire system. noise sources are inherently extremely stable devices. in addition, the circuitry is much simpler than a swept source which increases reliability and lowers cost. 4. amplitude reference source: the noise source can be used as a known reference signal. by switching in the noise source from the live signal, a quick test can be performed to check the health of the chain or calibrate the gain/loss. for this test, noise can be injected into the if system as well as the rf to test/calibrate the path. for more information on using noise for built-in-test, read the feb 2004 microwave journal article authored by patrick robbins of micronetics. http://www .micronetics.com/articles/microwave_journal_02-04.p df u u seful seful n n oise oise e e qua qua tions tions calculating y-factor: y fact = n 2 / n 1 where n 2 is measured power output with noise source on and n 1 is the measured power output with noise source off. calculating noise figure from enr and y-factor: nf(db) = enr (db) - 10 log10 (y fact -1) converting enr to noise spectral density (n 0 ): 0 db enr = -174 dbm/hz calculating noise power in a given bandwidth (bw) from noise spectral density: power (dbm) = n 0 + 10log(bw) * waveguide not available on s and l models f ullband h igh enr m icrowave n oise s ources s, c and x b ands
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