All CMOS GPS receiver with noise-matched high impedance on-chip antenna
View Patent ↗A GPS receiver depends on CMOS technology for both its GPS digital signal processing (DSP) and radio frequency (RF) stages. A resulting increase in RF input noise generated by the CMOS RF input is overcome by placing the antenna on-chip or on a lid of an application specific integrated circuit (ASIC) that includes the DSP and RF stages, and matching it for the best noise figure rather than the best impedance match. The on-chip antenna is matched to the natural high impedance of the CMOS RF input without requiring matching networks that can attenuate already weak signals. Using CMOS technology for both the GPS DSP and RF stages eliminates the need for level shifts between what would otherwise be a 3-volt RF section and a 1.2-volt DSP section.
1. A GPS receiver, comprising:
a radio frequency (RF) stage implemented with CMOS technology on a silicon semiconductor chip;
an on-chip antenna disposed on said silicon semiconductor chip and connected to provide GPS signal transmissions to the RF stage; and
a lossless matching network providing for an optimum noise figure match between the on-chip antenna and the RF stage;
wherein, a match between the on-chip antenna and the RF stage is not a best impedance match for maximum power transfer, but instead a match for a best noise-figure.
2. The GPS receiver of claim 1 , further comprising:
a baseband GPS digital signal processor stage connected to the RF stage and implemented to share said silicon semiconductor chip and said CMOS technology;
wherein, both the GPS digital signal processor and RF stages are operated at the same core voltages to eliminate any need for level shifters that would otherwise consume battery operating power.
3. The GPS receiver of claim 1 , wherein:
an input of the RF stage and on-chip antenna have impedances in excess of a megohm to reduce the noise that would be generated by the lossless matching network if they were fixed for traditional 50-75 ohm impedances.
4. A method for reducing power consumption in a portable radio receiver, comprising:
implementing a baseband digital signal processor and an RF stage in CMOS technology and operating them at the same core voltages to eliminate any level shifters that would otherwise consume battery operating power; and
matching an antenna to an input of said RF stage for optimum noise figure independent of best impedance matching.
5. The method of claim 4 , further comprising:
disposing said antenna on-chip with both said baseband digital signal processor and said RF stage.
6. The method of claim 4 , further comprising:
tapping said antenna at a high impedance point to match an input impedance of said RF stage that is in excess of a megohm.
7. A GPS receiver, comprising:
a radio frequency (RF) stage implemented with CMOS technology on a silicon semiconductor chip;
an ASIC-lid antenna disposed on a lid of an application specific integrated circuit (ASIC) that includes said silicon semiconductor chip and that is connected to provide GPS signal transmissions to the RF stage; and
a lossless matching network providing for an optimum noise figure match between the on-chip antenna and the RF stage.
8. The GPS receiver of claim 7 , further comprising:
a baseband GPS digital signal processor stage connected to the RF stage and implemented to share said silicon semiconductor chip and said CMOS technology;
wherein, both the GPS digital signal processor and RF stages are operated at the same core voltages to eliminate any need for level shifters that would otherwise consume battery operating power.
9. The GPS receiver of claim 7 , wherein:
an input of the RF stage and ASIC lid antenna have impedances in excess of a megohm to reduce the noise that would be generated by the lossless matching network if they were fixed for traditional 50-75 ohm impedances.
10. A method for reducing power consumption in a portable radio receiver, comprising:
implementing a baseband digital signal processor and an RF stage in CMOS technology and operating them at the same core voltages to eliminate any need for level shifters that would otherwise consume battery operating power;
disposing said antenna on a lid of an application specific integrated circuit (ASIC) that includes said both said baseband digital signal processor and said RF stage; and
matching an antenna to an input of said RF stage for optimum noise figure independent of best impedance matching.
11. The method of claim 10 , further comprising:
tapping said antenna at a high impedance point to match an input impedance of said RF stage that is in excess of a megohm.