Antenna and splitter for receiving radio and remote keyless entry signals
An antenna system may include a first antenna having a helical shaped portion, and configured to receive signals over a first frequency range. A second antenna may be positioned in proximate distance from the first antenna, and be configured to receive signals over a second frequency range. A splitter may be configured for separating signals received from radio and remote keyless entry antennas and may include a first branch including a first filter to filter AM band signals from communications signals received from an antenna, a second branch including a second filter to filter FM band signals from communications signals received from the antenna, a third branch including a third filter to filter remote keyless entry signals from communications signals received from the antenna, and an amplifier to amplify the remote keyless entry signals. The filters may be passive filters. The antenna maybe a whip antenna or roof antenna.
1. An antenna system, comprising: a first antenna having a helical shaped portion, said first antenna configured to receive signals over a first frequency range; and a second antenna positioned in proximate distance from said first antenna and configured to receive signals over a second frequency range, wherein said first and second antennas are each configured with an output portion and the output portions are connected to a common output that connects to a processing system, the first and second antennas configured such that the impedance of the first antenna approximately matches the impendence of the second antenna and the proximate distance being such that the first antenna effects radio frequency tuning of the second antenna.
2. The antenna according to claim 1 , wherein the first frequency range is an FM frequency band.
3. The antenna according to claim 2 , wherein said first antenna is further configured to receive signals over a third frequency range.
4. The antenna according to claim 3 , wherein the third frequency range is an AM frequency band.
5. The antenna according to claim 1 , wherein the second frequency range is an RKE frequency band.
6. The antenna according to claim 1 , wherein said second antenna is a stub antenna.
7. The antenna according to claim 1 , wherein the helical shaped portion has a length between approximately 18 cm and approximately 50 cm.
8. The antenna according to claim 7 , wherein the helical shaped portion has a diameter between approximately 0.5 cm and approximately 1.0 cm.
9. The antenna according to claim 7 , wherein said second antenna is a stub antenna having a length between approximately 5 cm and approximately 10 cm.
10. The antenna according to claim 1 , wherein said second antenna is a helical antenna.
11. The antenna according to claim 1 , wherein said second antenna is a meandering antenna.
12. The antenna according to claim 1 , wherein the proximate distance is between approximately 2 mm to approximately 4 mm.
13. The antenna system of claim 1 , further comprising: a splitter interconnected to connect with a single output from the connected output portions of the first and second antenna and to provide the output of the first antenna to a first device and provide the output of the second antenna to a second device, wherein the first and second device are designed to receive different signal frequencies.
14. The antenna system of claim 1 wherein the splitter provides the same transmission path for RKE transmissions as well as terrestrial radio transmissions.