Custom Component
IMM & IMB Series
IMAGE REJECT MIXERS
20 to 1000 MHz / Image Rejection Up to 30 dB / Internal Summing Quad Hybrid / Connectorized
Pkg
PRINCIPAL SPECIFICATIONS
SMA Model* BNC Model*
Number
Number
IMM-2D-***/
IMM-4D-***/
IMB-2D-***/
IMB-4D-***/
RF Center
Frequency, f
o
20 to 1000 MHz
20 to 300 MHz
LO
Bandwidth
10% of f
o
Octave
GENERAL SPECIFICATIONS
Impedance:
VSWR:
RF Input Power:
LO Power:
Conversion Loss:
Image Rejection:
IF Band:
RF Frequencies:
LO Bandwidth:
Weight:
Operating Temp:
50
Ω
1.5:1 max.
0 dBm max.
+10 t+13 dBm nom.
6 dB typ, 9 dB max.
25 dB typ, 20 dB min.
(See worksheet)
(See worksheet)
(See worksheet)
7.9 oz ( 223 g)
-- 55 to + 85°C
Model Numbering Note
*A complete model number shall be assigned upon
establishment of a full performance specification by the
factory in conjunction with the customer. The model
number shall include an indicator of the center frequency
(f
0)
and a special ‘‘slash’’ number to distinguish it from
related units. The format of model numbers is as above
where *** = f
0
.
General Notes:
1. Image Rejection Mixers are integrated networks composed of an in-phase power divider, two double
balanced mixers and two 90° quadrature hybrids. Their principal function is the separation of two signals
closely spaced in the frequency domain in, for example, a receiver’s IF stage.
2. An
image
is a spurious signal occurring in a receiver’s IF stage together with the
real
signal. Both
result from the mixing process. Normally, a passband filter selects the real signal while rejecting the
image. However, when the frequency difference between the real and image signals is relatively small,
conventional bandpass filters are generally inadequate.
3. In an Image Reject Mixer, the image is separated from the real signal by vector subtraction. The
resulting attenuation of the image is usually expressed as the ‘‘Image Rejection Ratio’’ in dB. (See
graph).
4. Several factors affect attainable image rejection. For example, image rejection is a function of
bandwidth, the phase and amplitude balances of the individual components chosen, mixer sensitivity
and VSWR interaction among other factors. The graph allows estimating attainable image rejection
under the variables of phase error and amplitude imbalance.
5. All Merrimac Image Reject Mixers comply with applicable sections of MIL-M-28837 and may be
supplied screened for compliance with additional specifications for military and space applications
requiring the highest reliability.
13Feb96
F rf t e if r to c n a t
M ERRI AC /41 Faifel Pl,W estCal
o ur h r n o ma in o t c
M
ri d .
dwel,NJ,07006 / 973- 1300 /FAX 973- 0531
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575-
575-
MERRIMAC [ MERRIMAC INDUSTRIES, INC. ]
