J. M. Kovitz and Y. Rahmat-Samii, “Using Thick Substrates and Capacitive Probe Compensation to Enhance the Bandwidth of Traditional CP Patch Antennas,” IEEE Transactions on Antennas and Propagation, vol. 62, no. 10, pp. 4970-4979, October 2014.
J. M. Kovitz and Y. Rahmat-Samii, “Using Thick Substrates and Capacitive Probe Compensation to Enhance the Bandwidth of Traditional CP Patch Antennas,” IEEE Transactions on Antennas and Propagation, vol. 62, no. 10, pp. 4970-4979, October 2014.