Antenna apparatus for radio-based electronic devices

A wireless radio communication terminal for a device having a working frequency, the terminal comprising:

• a housing having a top and sides defining an internal volume;
• at least an upper portion of the sides being metallic or metal coated;
• a printed circuit board having an electrically conductive surface;
• the printed circuit board being mounted in the internal volume so that edges of the electrically conductive surface are electrically connected at first and second locations to opposite surfaces of the sides of the housing thereby defining a subsection of the housing that is configured as a radio resonance cavity, in such a way that a current is allowed to flow from the housing to the electrically conductive surface at the first location, through the electrically conductive surface of the printed circuit board, and from the electrically conductive surface into the housing at the second location, wherein the radio resonance cavity is conductor-free;
• the electrically conductive surface of the printed circuit board having a wireless path length that substantially corresponds to one-half of a wavelength of the working frequency of the device;
• and
• wherein high-frequency energy to be emitted may be injected into the radio resonance cavity, or high-frequency energy to be received may be extracted from the radio resonance cavity.

A wireless radio communication terminal communicating using a working frequency, the terminal comprising:

• a housing having a top and sides defining an internal volume;
• and
• a printed circuit board, wherein:
• the printed circuit board is disposed to partition the housing into an enclosed space and a radio resonance cavity,
• the printed circuit board extends to the sides of the housing such that no openings exist in the ,printed circuit board between the enclosed space and the radio resonance cavity,
• the radio resonance cavity has a resonance at the working frequency,
• a first surface of the printed circuit board includes a conductive portion,
• the first surface of the printed circuit board faces the radio resonance cavity,
• the first surface of the printed circuit board has a wireless path length that substantially corresponds to one-half of a wavelength of the working frequency,
• sections of the sides of the housing surround the radio resonance cavity,
• at least a portion of the sections of the sides of the housing are conductive,
• a first end of the conductive portion of the printed circuit board is electrically connected to the conductive portion of the sections of the sides of the housing at a first location,
• a second end of the conductive portion of the printed circuit board is electrically connected to the conductive portion of the sections of the sides of the housing at a second location,
• energy to be emitted from the terminal is injected into the radio resonance cavity, and
• energy to be received at the terminal is extracted from the radio resonance cavity.