RF Electronics Chapter 5: Frequency Mixers Page 169
2022, C. J. Kikkert, James Cook University, ISBN 978-0-6486803-9-0.
device package is much smaller at 5.08x4.57 mm and is shown in the middle of figure
5.98.
3) MAC-24+ High Reliability DBM [27]. This DBM requires a +7 dBm LO signal and
has a LO/RF frequency range of 300 MHz to 2.4 GHz with a conversion loss of 6.5 dB.
The device package is a hermetically sealed package 7.62x6.35 mm shown on the right
of figure 5.98. This mixer is about 3 times the price of the other two mixers. The schematic
diagram for all these mixers is the same as figure 5.31.
The performance of the LTCC mixers is similar that of the Core & Wire mixers for the
same frequency range and LO level, but the LTCC mixers tend to cost less. More details
on LTCC circuits are given in chapter 11: Circuit Manufacture.
Figure 5.98. Mini-Circuits LTCC DBM packages 1) SM2 [25], 2) HV1195 [26], 3) DZ1650 [27].
MMIC Mixers
At microwave frequencies, the DBM can also be produced on silicon. Silicon has a
dielectric constant of 11.7 and the same techniques that can be used to make LTCC
DBMs, can also be used with silicon. MMIC transformers are typically made by precision
printing parallel lines as spiral inductors on a substrate. Including the diodes then result
in an MMIC mixer. Several manufacturers make MMIC mixers [2, 28-31]. These can be
either active mixers or passive mixers. As a typical example, the CMD251C3 [32] is a
passive 4 - 8.5 GHz fundamental mixer, that has a performance similar to high-level core
and wire DBMs, but uses a 3x3 mm SMT package.
Other Mixers
Mixer manufacturers make other types of mixers, such as DBMs using FETs in a passive
mode (no DC supplied to the FET) in order to obtain an improved IP3 performance. The
description of such devices are beyond the scope of these notes, but some further details
can be found at the Mini-Circuits web site (www.minicircuits.com).
Additional Resources
1 Mini-Circuits, Application notes on Frequency mixers AN00-001 to AN00-015
available from:
https://www.minicircuits.com/applications/application_notes.html or
https://blog.minicircuits.com/engineering-resources/ and then selecting
Frequency Mixers or Modulators/ Demodulators
2
Mini-Circuits, "RF Frequency Mixers", available from:
https://www.minicircuits.com/WebStore/Mixers.html
3 Stephen A Maas, "Microwave Mixers", Artech House, 2
nd
Ed, 1993.
RF Electronics: Design and Simulation
169 www.cadence.com/go/awr
