Update – CC1101 sensor node
I got a couple of reduced height quarter wave antennas since the half wave antennas are too big. Turns out they work equally well. These antennas are also less expensive. I also tested the performance with the antenna connected to the radio board through a sma cable assembly. You can see the pic below. The performance is similar to when the antenna is mounted on the RF board. Surprising since quarter wave antennas require a good ground plane (provided by the RF board when mounted on it) to perform. This allows us to put the node in an enclosure and mount the antenna on the outside.
I also used non-stackable connectors (to connect the micro board to the radio host board) on a node instead of stackable connectors. The downside is that the radio cannot be changed. The upside is that these non stackable connectors are pretty cheap. These connectors are also from Samtec.