[hpsdr] Interesting articles in Microwave & RF April 208 issue

[Giancarlo Moda]

Hi all,

In the Microwave & RF  April 2008 issue there are two
interesting articles.

1)
Large-Signal Approach Yields Low-Noise VHF/UHF
Oscillators 
In contrast to traditional small-signal approaches,
the use of large-signal, time-domain design techniques
helps deliver low-noise grounded-base oscillators for
VHF/UHF applications.

Ajay Kumar Poddar, Ulrich L. Rohde  

Although a lot of mathematics involved there is an
interesting circuit diagram for an oscillator running
at 144MHz that should help to understand the design.
144Mhz use is certainly a selection due to our friend
N1UL. Congratulations Ulrich. You may read the article
at:

http://www.mwrf.com/Articles/ArticleID/18646/18646.html

2)
Cut Loss In Low-Voltage, Wideband PIN Attenuators 
Variable attenuators based on the pi (p) configuration
can be designed with frequency coverage spanning
multiple octaves, from the high-frequency (HF) range
to the lower microwave region. As a result, they are
suitable for numerous wideband applications, such as
in satellite television and cable-television (CATV)
systems. The use of PIN diodes in these attenuators
enables them to be realized as low-cost components and
compact alternatives to ...  — Chin-Leong Lim

This is a quite clear reading and also good learning
about a solution on how to improve PIN attenuators
with low voltage control. See


http://www.mwrf.com/Articles/ArticleID/18648/18648.html

Best 73

Gian
I7SWX



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