Unintentional RF radiators filter protection for a cospas sarsat emergency locator transmitter (ELT) GNSS receiver
AssigneeACR Electronics, Inc.
InventorsWilliam Cox, Irek Gora
Life of this patent
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Abstract
This invention relates to an emergency locator transmitter (ELT) that transmits an emergency signal to a global navigational satellite system (GNSS) indicating an aircraft crash location, or an aircraft distress tracker event signal that triggers the ELT to provide location of the aircraft, the ELT including a GNSS RF receiver. The invention ELT includes 406 MHz RF signal blanking switch, a GNSS high pass filter, RF radiator and EMI filter protection for the GNSS receiver to protect the GNSS receiver from 406 MHz emergency signals, unintentional RF radiators and electromagnetic interference (EMI) typically found in aircraft.
Claims2
An COSPAS SARSAT emergency locator transmitter (ELT) that includes a 406 MHz transmitter and Global Navigation Satellite System (GNSS) receiver, for use in an aircraft, the improvement comprising:
- an ELT transmitting and receiving antenna connected to said 406 MHz signal transmitter output;
- and
- said ELT transmitting and receiving antenna connected to a 406 MHz blanking switch, the 406 MHz blanking switch connected to a GNSS high-pass filter connected to said GNSS receiver, protecting the GNSS receiver from unintentional radio frequency (RF) radiators, electromagnetic interference (EMI), and 406 MHz signals;
- a first surface acoustic wave (SAW) filter connected between said GNSS high-pass filter and said GNSS receiver to protect the GNSS receiver from unintentional RF radiators;
- and
- a second surface acoustic wave (SAW) filter connected between said first SAW filter and said GNSS receiver, to further protect the GNSS receiver from unintentional RF radiators, EMI, and 406 MHz signal RF harmonics.
Dependencies are inferred from the claim text.