Page 444 - Complete Wireless Design

Wireless Issues

Wireless Issues 443

10.9.2 Types of connectors
There have been many connectors invented and manufactured over the years
for different frequencies and applications, as well as to improve ease of use
and performance. The following connectors are the most common found today
for coaxial connections from HF to SHF:

UHF—Developed by Amphenol in the 1930s, the UHF connector is utilized
in RF applications up to only 300 MHz. This frequency limitation is a result
of their undesirable nonconstant impedance characteristics. Also called a
PL-259 connector, it is operated in low-cost, undemanding service.
N—Developed at Bell Labs, the N connector is the foremost connector for
test equipment and antenna interfaces up to 4 GHz. They are 50-ohm
threaded units that are capable of operating up to 11 GHz.
BNC—Can function up to 3 GHz, but normally found on lower-frequency,
lower-cost test equipment, as well as antenna connections. Both 50- and 75-
ohm versions are available.
TNC—A threaded version of the BNC connector, but designed for high-
vibration environments up to 10 GHz.
SMA—The dominant 50-ohm microwave connector, capable of operation at
up to 20 GHz. They are quite small and have threaded connections.
SMB—Nonthreaded, push-on connector operational up to 4 GHz, and
available in both 50- and 75-ohm versions.
APC-7—A sexless screw-in, very high performance microwave connector
qualified up to 18 GHz. Because of their very high cost, they are almost
exclusively found only on high-end (Agilent) test equipment.
3.5MM—A precision version of the SMA connector, it can function up to 34
GHz. It has an air dielectric for increased performance over that of the SMA
type. 3.5MMs will maintain their operational characteristics for thousands
of connects/disconnects.
Wiltron-K—A sturdy, high-frequency (40-GHz) connector that will also mate
with the SMA type if so required.

10.10 Wireless Design Software
10.10.1 Introduction
The computer and specialized simulation software have become invaluable
tools in wireless circuit design during the last 20 years. Many software pro-
grams are available that can assist the engineer in optimizing a circuit for
increased gain, frequency, output power, stability, etc., that would just not be
possible without computer simulation capabilities in the shortened time frame
permitted in modern industry. This is true not only on the circuit design level,
but also in wireless system design.

Downloaded from Digital Engineering Library @ McGraw-Hill (www.digitalengineeringlibrary.com)
Copyright © 2004 The McGraw-Hill Companies. All rights reserved.
Any use is subject to the Terms of Use as given at the website.