what is a proper circuit for RF switch matrix in microwave frequencies?
There are many choices now, but the most cost-effective is GaN on SiC, while faster chips can use Diamond substrate.($)

These about the size of a grain of rice and can switch up to 6GHz at 20MHz rate.



Frequency Range: 0.5 - 6 GHz
• Insertion Loss: ≤ 0.8 dB
• Power Handling: 46 dBm (P.1dB)
• Return Loss: &gt; 15 dB
• Isolation: &gt; 26 dB
• Control Voltages: 0 V/-40 V (from either side of the
MMIC)
• Switching Speed: &lt; 50 ns
• Reflective Switch
• Die Dimensions: 1.397 mm x 1.580 mm x 0.10 mm

The TriQuint TGS2354 is a Single-Pole, Double-Throw
(SPDT) reflective switch fabricated on TriQuint's
TQGaN25 0.25um GaN on SiC production process.
Operating from 0.5 to 6GHz, the TGS2354 typically
supports up to 40W input power handling at control
voltages of 0/-40 V. This switch maintains low insertion
loss of 0.8 dB or less, and greater than 25dB isolation
making it ideal for high power switching applications
across both defense and commercial platforms..
The TGS2354 is available in a small 1.397 x 1.58 mm
die size and allows control voltage input from either side
of the die. This, along with the minimal DC power
consumption, allows for easy system integration.