I'd like to suggest another option. I have some Platinum RTD temperature sensors bought for another project. They are very stable and accurate as temperature sensors and relatively cheap. They are also very small - small enough to be used as an RF load in a BNC or SMA fixture, with bandwidth extending, possibly, to the low GHz region. Mine have leads; but they are available in surface mount packages. 100 Ohms is the most commonly supplied resistance; so 2 in parallel could make a nice 50 Ohm load.? A third sensor could serve as a reference in a bridge circuit. Alteratively, one might preheat to a known temperature with DC and measure the DC power drop required to achieve the same temperature with RF applied. Other readout options also exist, including lock-in if the RF power can be modulated.
Stephen Menasian
Stephen Menasian
