Multi-frequency Miniaturized RF Components Using Hybrid Substrates

This paper has demonstrated using a combination of dielectric and magneto-dielectric substrates to reduce the form factor of transmission line-based RF circuits and antennas while simultaneously achieving low-loss at high frequency. As the demand for small form factor and multiple frequency band operability increases, the need for miniaturized antennas and low loss microstrip lines increases. We used RO4350B and Magtrex substrates to demonstrate a dual-band meandered dipole antenna resonating at 400 MHz and 900 MHz frequency bands. As the magneto-dielectric material becomes lossy at high frequency, the efficiency of the RF components reduces. The hybrid design provides an avenue to overcome this challenge. The antenna's size is reduced by 14% using the hybrid substrate design compared to a similar antenna realized on RO4350B substrate. However, the antenna gain is reduced by approximately 0.65 dBi at 900 MHz. A balun structure on magneto-dielectric substrate is also demonstrated. Full EM simulation using a commercial tool was carried out, and a good correlation between simulation and measured results was achieved.