| 26
From Fab to Function: RF Circuit &
Interconnect Technologies
Modern RF systems depend on
precise circuit fabrication and
interconnect technologies to
provide reliable, high-frequency
performance. From wireless
communication to radar to
advanced sensing applications,
RF circuits must be carefully
designed to handle signal integrity,
minimize loss, and meet demanding
performance requirements.
RF components and devices
are manufactured, assembled,
and connected (electrically and
physically) in various ways to meet
diverse end-user requirements.
The basic RF circuits within
many RF system modules are RF
circuit boards or planar circuits
fabricated using planar circuit
technologies. These RF circuits are
then connected to other circuits
using RF interconnects, such as
waveguides, coaxial connectors,
or wire bonds. RF circuits can be
connected within the same housing,
between housings, or even between
systems using RF interconnects.
This chapter presents an
overview of various RF circuit
fabrication technologies and
the most common types of RF
interconnects, with an emphasis
on coaxial cables and connectors.
It details the key technologies,
material considerations, and
performance trade-offs
engineers should understand
when developing RF systems.
RF Circuit Fabrication
Technologies
Three primary materials are used
to make nearly all RF circuits:
conductors, dielectrics, and
semiconductors. For ease of
machining, process control, and
other factors, most RF circuits
are developed using planar circuit
technologies, employing methods
such as printed circuit boards
(PCBs), flexible PCBs, high-
temperature co-fired ceramics
(HTCCs), low-temperature
Image Source: Audrius Merfeldas/stock.adobe.com
