[hpsdr] High Power Amplifiers - Tracking Power Supplies

[Dr. Jim Rothwell]

Hi,

Thanks to all for the excellent contributions to this list.

Just to comment on what many may already know, tracking power supplies 
have been used sucessfully
for quite some time. A decade or more ago, Bob Carver used one in an 
audio power amplifier, Sunfire I
think. As I recall, it maintained the DC supplies about 6V greater than 
the required value the amp needed
for the signal at any given moment. They sounded great to me and had low 
dissipation for a multi-FET design.

And if memory serves, the principle dates back even further.

There are some excellent high power class-d integrated amplifier chips 
now, like the TDA8954, which might
potentially serve as the starting point for a tracking supply. Capable 
of 400+w, about $9USD.

Best,

Jim Rothwell
St. Ann, MO
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Date: Fri, 23 Jul 2010 12:24:07 +0200

>From: "Ben Witvliet" <pa5bw at xs4all.nl>
>To: <hpsdr at lists.openhpsdr.org>
>Subject: [hpsdr] EER finals, predistortion
>Message-ID: <002101cb2a51$2ef7cb20$8ce76160$@nl>
>Content-Type: text/plain; charset="iso-8859-1"
>
>Dear all,
>
> 
>
>I found the following (commercial) publication on very high efficiency RF
>power amplifiers:
>
> 
><http://www.mathworks.nl/company/newsletters/digest/2010/july/nujira-amplifi
>er-performance.html?s_v1=13445411_1-6XCKGU>
>http://www.mathworks.nl/company/newsletters/digest/2010/july/nujira-amplifie
>r-performance.html?s_v1=13445411_1-6XCKGU
>
>It is of course a success story describing the benefit of their own product,
>but the message I get from it: EER as we meant to achieve in Thor can be
>done. 
>
> 
>
>Also the article mentions the use of predistortion to create a very linear
>amplifier. I heard that before from an English consultant (For my QRL I
>participate in European standardization work). He said that mobile phone
>network operators had great success with predistortion to get rid of IMD
>products on combined installations. So I see the remark in this document as
>a confirmation that that has become feasible with ?average? means. I haven?t
>seen any amateur publications yet on the use of non-linear or not-so-linear
>amplifiers and predistortion. With the processing power we have in HPSDR
>this may come within reach.
>
> 
>
>By the way: as a MatLab user I?m very interested in using Simulink to
>simulate such applications. Makes it possible to replace the MatLab software
>blocks bit-by-bit by real-life hardware.
>
> 
>
>Justed wanted to share this information with you.
>
> 
>  
>
>  
>