Microwave apparatus and method

A microwave apparatus according to wherein:

• a) the at least one longitudinal slot is a single longitudinal slot;
• or
• b) the at least one longitudinal slot is a radially opposed pair of longitudinal slots;
• and/or
• c) the radiating element comprises a monopole antenna.

A microwave system comprising:

• a microwave generator;
• a controller configured to control the microwave generator to generate microwave energy having a selected operational frequency or range of frequencies;
• a microwave feed line configured to deliver the microwave energy to a radiating element extending from or coupled to a distal end of the microwave feed line;
• the radiating element;
• and
• a reactive element formed in or on the microwave feed line;
• wherein the operational frequency or range of frequencies is selected such that the reactive element both provides a desired degree of match between an impedance of the radiating element and an impedance of the microwave feed line and reduces or eliminates surface currents flowing on a ground of the feed line.

A method comprising:

• controlling a microwave generator to generate microwave energy having a selected operational frequency or range of frequencies;
• and
• delivering by a microwave feed line the microwave energy to a radiating element extending from or coupled to a distal end of the microwave feed line, wherein a reactive element is formed in or on the microwave feed line;
• wherein the operational frequency or range of frequencies is selected such that the reactive element both provides a desired degree of match between an impedance of the radiating element and an impedance of the microwave feed line and reduces or eliminates surface currents flowing on a ground of the feed line.

A method of designing a microwave apparatus, the method comprising:

• simulating operation at a selected frequency or range of frequencies of a radiating element extending from or coupled to a distal end of a microwave feed line;
• and
• performing an iterative design procedure comprising:
• simulating detuning of the radiating element;
• and
• selecting reactive properties of a reactive element formed in or on the microwave feed line, the iterative design procedure being repeated until at the selected frequency or range of frequencies the reactive properties of the reactive element provide a desired degree of match between a simulated impedance of the radiating element and a simulated impedance of the microwave feed line while reducing or eliminating simulated surface currents flowing on a ground of the feed line.

A method of fabricating a microwave apparatus, the method comprising:

• providing a coaxial cable;
• at a distal end of the coaxial cable, selectively removing a distal portion of the outer conductor of the coaxial cable to expose a distal portion of the inner conductor to form a radiating antenna element;
• selectively removing at least one further portion of the outer conductor of the coaxial cable, thereby forming at least one aperture in the outer conductor of the coaxial cable,
• wherein parameters of the at least one aperture are selected to provide a desired degree of match between an impedance of the radiating element and an impedance of the microwave feed line and to reduce or eliminate surface currents flowing on a ground of the feed line, when operated at a selected operational frequency or range of frequencies.