IMF-2 Series
IMAGE REJECT MIXERS
10 to 3000 MHz / Rejection Ratios up to 30 dB / Internal Summing Quadrature / Hi-Rel Package
PRINCIPAL SPECIFICATIONS
DUAL MIXER IMAGE REJECTION
50
for a given Amplitude and Phase Balance
Model
LO Center Bandwidth Outline
Number Freq, f
o
, MHz
MHz
Style
IMF-2F-***/ 10 - 1000
IMF-2L-***/ 1000 - 3000
10% of f
o
10% of f
o
F
L
45
Image Rejection (dB)
MODEL NUMBERING NOTE
A complete model number shall be assigned upon estab-
lishment 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
o
) and a
special slash number to distinguish it from related units.
The format of model numbers is as above where *** =f
o
.
Ampli.
Balance
0.0 dB
0.25 dB
0.5 dB
40
35
Image
Rejection
Ratio
30
GENERAL SPECIFICATIONS
(as a Down Converter)
25
0.75 dB
1.0 dB
20
2.0 dB
15
0.5
1
1.5
2
2.5
3
RF/LO Input Characteristics
Impedance:
50
Ω
nom..
VSWR:
1.5:1 max.
RF Power Level:
0 dBm nom.
LO Power Level:
+10 dBm nom.
IF Bandwidth:
up to an octave
RF Bandwidth:
up to an octave
LO Bandwidth:
10%
Output Characteristics
Conversion Loss:
9 dB max.
Image Rejection:
25 dB min.
Temperature Range:
-- 55° to +85°C
Phase Error (degrees)
(For Bandwidth as above)
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. Merrimac offers a wide range of Image Reject Mixers for numerous applications. All units are designed and built in accord with applicable
specifications. Designers are invited to work closely with Merrimac engineers to insure best results.
6. 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.
24Apr96
F rf t e if r to c n a t
M ERRI AC /41 Faifel Pl,W estCal el,NJ,07006 / 973 575-
o ur h r n o ma in o t c
M
ri d .
dw l
1300 /FAX 973- 0531
575-
MERRIMAC [ MERRIMAC INDUSTRIES, INC. ]
