Compact printed antenna for radiation at low elevation

A flat printed antenna for transmission and/or reception of microwave signals, the antenna comprising:

• a plate of dielectric substrate;
• an earth plane formed by a first conductor layer deposited on a first face of said plate of dielectric substrate;
• a radiating element formed by a second conductor layer deposited on a second face of said plate of dielectric substrate;
• and
• means of feeding said antenna said feeding means using a feed technique belonging to the group that includes:
• feed by a coaxial probe;
• feed by proximity coupling;
• feed through a feed line in the plane of the radiating element;
• and
• feed by coupling through slits;
• said antenna having a fundamental mode, in which it generates a radiation pattern having a maximum in the direction perpendicular to the plane containing the radiating element, and at least one higher mode, in which it generates a radiation pattern at low elevation, characterized in that said radiating element has at least one slot allowing the control of the resonance frequency of a chosen higher mode.

A flat printed antenna for transmission and/or reception of microwave signals, the antenna comprising:

• a plate of dielectric substrate;
• an earth plane formed by a first conductor layer deposited on a first face of said plate of dielectric substrate;
• a radiating element formed by a second conductor layer deposited on a second face of said plate of dielectric substrate, the radiating element being in the form of a disc, said radiating element having four radial slots spaced two by two at angles of about 90 degrees;
• and
• means of feeding said antenna;
• said antenna having a fundamental mode, in which it generates a radiation pattern having a maximum in the direction perpendicular to the plane containing the radiating element, and at least one higher mode, in which it generates a radiation pattern at low elevation, characterized in that said four radial slots of said radiating element allow the control of the resonance frequency of a chosen higher mode wherein said chosen higher mode is the TM21 mode, whose current lines form a pattern that is repeated in each quarter of said disc, each of said four radial slots being approximately perpendicular to the current lines of one of said disc quarters.

A flat printed antenna for transmission and/or reception of microwave signals, the antenna comprising:

• a plate of dielectric substrate;
• an earth plane formed by a first conductor layer deposited on a first face of said plate of dielectric substrate;
• a radiating element formed by a second conductor layer deposited on a second face of said plate of dielectric substrate, the radiating element being in the form of a disc, said radiating element having at least one circular slot extending over at least a part of the circumference of a circle contained within said disc and disposed concentric therewith;
• and
• means of feeding said antenna;
• said antenna having a fundamental mode, in which it generates a radiation pattern having a maximum in the direction perpendicular to the plane containing the radiating element, and at least one higher mode in which it generates a radiation pattern at low elevation, characterized in that said radiating element has at least one slot allowing the control of the resonance frequency of a chosen higher mode wherein said chosen higher mode is the TM01 mode, the current lines from which are arranged radially.

A flat printed antenna for transmission and/or reception of microwave signals, the antenna comprising:

• a plate of dielectric substrate;
• an earth plane formed by a first conductor layer deposited on a first face of said plate of dielectric substrate;
• a radiating element formed by a second conductor layer deposited on a second face of said plate of dielectric substrate;
• and
• means of feeding said antenna;
• said antenna having a fundamental mode, in which it generates a radiation pattern having a maximum in the direction perpendicular to the plane containing the radiating element, and at least one higher mode, in which it generates a radiation pattern at low elevation, characterized in that said radiating element has at least one slot allowing the control of the resonance frequency of a chosen higher mode, each of said at least one slot having disabling means, and wherein the antenna includes activation/deactivation means for activating and deactivating said disabling means.

A two band antenna comprising:

• a lower antenna and an upper antenna superimposed thereon, each antenna comprising:
• a plate of dielectric substrate;
• an earth plane formed by a first conductor layer deposited on a first face of said plate of dielectric substrate;
• a radiating element formed by a second conductor layer deposited on a second face of said plate of dielectric substrate;
• and
• means of feeding said antenna;
• said antenna having a fundamental mode, in which it generates a radiation pattern having a maximum in the direction perpendicular to the plane containing the radiating element, and at least one higher mode in which it generates a radiation pattern at low elevation, characterized in that said radiating element has at least one slot allowing the control of the resonance frequency of a chosen higher mode, wherein the radiating element of said lower antenna forms the earth plane of said upper antenna.