This project would not be possible without the original ideas from several amateurs and the continuing help from Mark N0IO, and Al W5LUA. The project started in 2005 and as of 2010 has resulted in sufficient quality and performance that the time is at hand to build a quantity for amateur need.

The LNA consists of a bias board on the bottom and two UMS MMIC Amplifiers in series - the CHA 1077A-98. The bias board was adapted from a DB6NT design. The completed unit requires 11 to 15 VDC at 100 to 110 mA. The waveguide is WR12 (WG26) and the intput and output ports are in-line.

Below is a photo showing the development with three versions.

Above is rev 4

And again a photo of Rev 4 - in this revision the waveguide ports are in-line

Of the most recent units constructed, all have achieved a noise figure below 4 dB, in fact all were below 3.5 dB at 78.192 GHz using equipment which although not calibrated to NIST standards appear to be reporting correct results. Check back here for any further information about performance measurements.

Unit number	Gain	Noise Figure
1	27.7	3.16 dB
3	30.5	3.37 dB
6	29.7	3.0 dB

The units constructed so far achieve between 27 and 30 dB gain at 78.192 GHz, as shown in the graphs below.

I had originally hoped to be ready to take orders around early in 2011. However, becuase of a recent illness and death in my family, I could not work on this project, and so I have had a slip of at least four months

This means sometime in June I may be ready to take orders

Please check back here to get the latest information.

Here is the plan.
0) Modify block design for necessary changes and new plating spec.
1) Get new blocks made and plated,
2) Assemble two new blocks
3) Test and verify new blocks
4) Announce and Take orders
5) Order blocks and components
6) Build
7) Test, fix
8) Ship
May 4 - We have completed step 0. Drawings are being verified before milling machine will be programmed.

August 12 - We have received the latest blocks, so step 1 is done.

September 6 - we have dry fit parts and found that an error was introduced in the bias board mounting. We will modify a few bias boards for now to test these blocks and then have new bias boards made with the modificaiton.

October 10 - We assembled 4 blocks - MMICs, Caps, Feedthrus, RF boards, ribbon bonding. Assembled 4 bias boards, but found out of a few parts, built one completely, other 3 awaiting two parts should arrive Oct 11.

Have to test all bias boards prior to insertion to make sure that they work properly so that we don't destroy expensive MMICs. Have not tested any yet,

Discovered that noise figure measurement setup requires good filter. Designed, began to machine, had problems.

Expect to deliver report at Microwave Update in a few days.

Almost completed step 2, October 10.

A message will be sent out on the microwave reflectors when any change, such as being ready to take orders, occurs. Instructions will also be given via those channels and this one.

Thanks for your continued patience.

Tom WA1MBA

This page was last updated October 10, 2011