Integrated multiband antenna
An end fed dipole antenna on a circuit board configured to be a multiband, portable radio antenna has, among other features, an integrated diplexer for operating the antenna in multiple frequency bands.
1. An integrated multiband antenna characterized by:
at least one L-band end-fed dipole on a circuit board inside an upper end of a dielectric radome;
a center trace element extending along the length of the circuit board from a lower end to a feed point of the at least one L-band dipole and electrically coupled to a conductor;
a UHF dipole inside the dielectric radome and electrically coupled to the conductor;
a helical coil of semi-rigid coax coupled to the center trace element to form a high impedance inductor at UHF frequencies;
a diplexer circuit connected to the helical coil inside the dielectric radome to combine L-band and UHF signals into a single into a single cable; and
a balun or a transformer within the radome that transforms impedances at VHF frequencies, wherein the single cable passes though the balun or transformer.
2. The integrated multiband antenna of claim 1 wherein the impedance of the circuit board is configured to enable the circuit board to act as an upper element of the UHF dipole.
3. The integrated multiband antenna of claim 2 further comprising a cable connected to the diplexer and a radio chassis connected to the cable wherein the cable and the radio chassis form a lower element of the UHF dipole.
4. The integrated multiband antenna of claim 1 wherein the at least one L-band end-fed dipole on the circuit board includes dielectric tuning slots.
5. The integrated multiband antenna of claim 1 configured as one of a hand-held antenna, a man-pack antenna, a vehicular antenna, or a linear envelope.
6. The integrated multiband antenna of claim 3 wherein the cable is a goose-neck cable.
7. The integrated multiband antenna of claim 1 further comprising a connector adapter carrying a multiplexer circuit configured to separate the bands in the integrated multiband antenna and direct each separate band to a different connector.
8. The integrated multiband antenna of claim 1 wherein an inner tube over the at least one L-band end-fed dipole on the circuit board includes conductive closed sleeves.