Unfortunately, i do not have this pcb anymore. Too much solder can indicate via on the right side of varactor, but DC biasing looks impossible to achieve this way. But it was two-layer PCB, innel layer may have answers.
If solder dot is treated like lambda/8...lambda/16, there are small phase tuning still using varactor.
There is one question bothering me for a long time:
Many designs with DC-block (marked "1" on this image) have wide area right before dc-block thin coupled lines. Many microstrip band-pass filters made this way too: there is pretty wide area placed right before filter and after filter. I read some books, did some calculations. There is odd impedance, even impedance, coupled lines analysis and similar stuff. But it is all about filter or coupler itself. None of books i read consider this quarter-wave(?) area right before coupled part starts. So what is this thing? It looks like quarter-wave transformer. It is very wide, so it looks that they try to achieve very low impedance, but why?
I have two theories:
1) calculated line width for Z0=50 Ohm are too thin, or not optimal, so they use some 20 Ohm, etc..
So all coupled elements will have different width. But here it is unclear how they decide wich Z0 is good for filter input and output.
2) some other reason i do not know yet.
Another thing is marked "2" on image. It is half-wave resonator in microstrip parallel feedback oscillator. Interesting thing is that it is connected to phasing line. What is the purpose of such connection?
1) To obtain lower Q-factor? (to obtain wider frequency tuning using varactor)
2) To add more power into feedback?