[time-nuts] DIY QFH

[Attila Kinali]

On Tue, 26 Nov 2013 11:37:10 -0500
"quartz55" <quartz55 at hughes.net> wrote:

> Does anyone know what is inside the commercial units, like the PCTEL GPS-TMG-HR-26N I have?

Three types of GPS antennas are common:
* ceramic carrier patch antennas
* cross dipole antennas
* helical designs

The patch antennas are even found in "expensive" antennas with cones
or choke rings. 

The Trimble Bullet antenna is AFAIK a cross dipole type where the dipole
ends are bend down for a more GPS like radiation pattern.

Helical designs vary greatly in their fabrication. I think most of the
newer ones use some flex PCB that is bend into a pipe shape to form the
helix (very cheap from a manufacturing point of view).
High quality helix are either free space (like your QFH) or done on some
ceramic pipe. I'm not aware of anyone using MID (molded interconnect device)
for this kind of antenna. Although MID antennas have been the standard
for cellphone antennas for quite some time already.



-- 
The trouble with you, Shev, is you don't say anything until you've saved
up a whole truckload of damned heavy brick arguments and then you dump
them all out and never look at the bleeding body mangled beneath the heap
		-- Tirin, The Dispossessed, U. Le Guin