Engineered High Resistivity Silicon Substrates in IPD Technology Used for Miniaturized sub-6 GHz Filters

Engineered surface passivated high resistivity silicon (Si) substrates have been developed to improve performance of radio frequency devices. Measurements show that substrate dominant 2
^nd
harmonics generation can be reduced by up to 20 dB at 1 GHz by using engineered substrates. Both capacitively and magnetically coupled band-pass filters were designed for integrated passive devices (IPD) process to compare different substrates and to realize new designs. Usage of engineered high resistivity Si substrates resulted in losses as low as with quartz/fused silica substrates, which is significant improvement to standard high resistivity silicon substrates. Additionally, the compact magnetically coupled filter topology shows freedom to choose transmission zeros for unwanted frequencies.