I've been looking around for amplifiers for a multiple amplifier setup for a HF phased array (one where there's an amplifier for each element). Power output per amp should be in the 200-400 W range.
Another requirement must be repeatable or adjustable phase and power control. unless you are planning to have an output sample feedback to your phase shift and power divider network to compensate for
your Feedback and real time adjustment is a given... Even in an all passive array, one needs this. I'm just looking for "gain blocks" that are available essentially off the shelf and won't require ex
an all passive essentially off the redesign/modification/extra parts. Sure.. relays, for instance, There's more with motorized You'd better look close at IMD. Solid state amps are generally ratty. T
Of course, meaningful IMD specs are somewhat hard to come by (at least in the mfr literature). It turns out that one can (usually) find a phasing configuration that optimizes power squirted in a part
Sure Nope One calibrates the system, at full power (because phase shift through the amplifier varies with power). In practice, one calibrates the components infrequently to get close (i.e. you build
of switch middling high posts) Sounds like a great system if you want less significantly than 1500 watts output, pee-poor IMD, and have time and money to burn. Compare that to a the same general Exc
Jim, Really interesting work. I was familiar with some "electronically steerable array" stuff in the early 70's (Higher frequency). The concepts applied to HF could have some very interesting amateur
Why would you have less power with multiple amplifiers than with a single amplifier (assuming comparable radiating elements, of whatever form)? The "antenna loss" is mostly geometry determined, and i
Jim, I have been dreaming about the same kind of active TX/RX array you are talking about. Since I have been considering doing it for 160m QRP, I have envisioned each "final amp" to be broadband opam
The performance of any phased array is critically dependent upon proper [phasing] and [amplitude] of the power delivered to each element in the array. If we consider only the transmitting case, this
This is a pretty interesting discussion. I don't quite have my head wrapped around a few of the issues, but I would like to make the following comments: 1). The concept Jim describes is used at highe
along a chain the fence). chain link 30' 4 sides (and assuming based using the combined couplers to No advantage I know of. But then sometimes people build things just to build them. Arrays like thi
Yes.. scan blindness is a problem where the elements are evenly spaced in a uniform environment. As a practical matter, it's not likely to occur in a ham installation. As you say, a lot has to do wi
Besides the DSP predistortion you mentioned, what are these "new amplifier design approaches?" Do they work with an arbitrary load impedance? What kind of efficiency are you thinking of? BTW, DSP pre
There's have seems Some interesting class E designs have been demonstrated by Dave Rutledge at Caltech using really cheap MOSFETs. These are narrowband, however, and also require somekind of envelope
There's have seems I was thinking, in general, of things like envelope elimination/replacement, or various modifications of outphasing, all of which can use high efficiency stages (like, for instance
Unfortunately, there is no response from that site. Assuming from the URL that you have some NASA connection, you might be able to locate some possibly relevant information on the phased arrays used
The stuff there has been released for public distribution, but perhaps that site hasn't. I'll ask. In the mean time: http://www.luxfamily.com/jimlux/R04026011.pdf should work I'll take a look. There'