Silicon Substrate Surface Conduction and Dielectric Passivation Fundamentals
Trap-rich polysilicon passivation pins interface charges on high-resistivity silicon, suppressing surface conduction and harmonic spur spikes across RF switches.
Receive Sensitivity Loss
Meaning
A reduction in the ability of a wireless receiver to detect weak signals often arises from internal noise or electromagnetic interference. Measurement of receive sensitivity loss quantifies this degradation in decibels, showing how much the minimum usable signal level has risen. This metric directly affects the operational range of a connected device.
Noise Source
Electromagnetic emissions from nearby high-speed processors or switching power supplies can couple into the antenna path. This coupled noise raises the noise floor of the receiver, masking low-power incoming signals. A severe receive sensitivity loss occurs when these spurious signals fall directly within the operating channel of the radio.
Coexistence Challenge
Co-located transmitters, such as those for Wi-Fi and Bluetooth on the same board, can desensitize the primary receiver. High-power leakage from the transmitter bypasses the front-end filters and saturates the low-noise amplifier. When this desensitization happens, the system experiences a temporary rise in packet error rates.
Mitigation Design
Shielding enclosures and board-level partitioning are deployed to isolate the sensitive analog front end from digital noise sources. Designers select bandpass filters with high out-of-band rejection to protect the receiver from nearby transmit signals. Automated testing in an anechoic chamber verifies that the receive sensitivity loss remains within acceptable limits when all onboard subsystems are operating at full capacity.
This verification step ensures the device maintains a stable connection in complex radio environments.