Antenna assembly and portable radio apparatus

An antenna assembly comprising:

• a fixed helical antenna including a first conductive terminal;
• a rod antenna extending through an inside of said fixed helical antenna in an axial direction thereof and being slidably mounted for movement in said axial direction between an extended position and a retracted position, wherein said rod antenna is electrically isolated from said fixed helical antenna in both said extended position and said retracted position and includes:
• a conductive portion formed in a proximal portion of said rod antenna, wherein said conductive portion terminates in a second conductive terminal at a proximal end of said conductive portion of said rod antenna, and wherein when in said retracted position a distal end of said conductive portion of said rod antenna is positioned below a proximal end of said fixed helical antenna;
• a non-conductive bar member having a length greater than an axial length of said fixed helical antenna so that said non-conductive bar member is placed inside said fixed helical antenna when said rod antenna is in said retracted position for electrically isolating said rod antenna from said fixed helical antenna;
• and
• switching means for switching a power supply to one of said fixed helical antenna and said rod antenna in accordance with a position of said rod antenna.

An antenna assembly comprising:

• a fixed helical antenna formed in a cylindrical shape having a constant first diameter including first and second annular conductive terminals having a central aperture of a second diameter located respectively at distal and proximal ends thereof;
• a rod antenna extending through an inside of said fixed helical antenna in an axial direction thereof and being slidably mounted to extend and retract in said axial direction, wherein said rod antenna includes:
• a conductive portion formed in a proximal portion of said rod antenna, wherein said conductive portion terminates in a third conductive terminal of a length substantially equal to an axial length of said fixed helical antenna and having a diameter equal to said second diameter;
• a non-conductive bar member formed in a distal portion of said rod antenna having a length greater than an axial length of said fixed helical antenna so that said non-conductive bar member is placed inside said fixed helical antenna when said rod antenna is in said retracted position for electrically isolating said rod antenna from said fixed helical antenna, wherein
• said first and second annular conductive terminals are electrically shorted by said third conductive terminal of said rod antenna and said third conductive terminal forms an environmental seal with said first conductive terminal when said rod antenna is in said extended position.

An antenna assembly comprising:

• a fixed helical antenna;
• and
• a rod antenna positioned coaxially with said helical antenna, wherein
• said rod antenna is formed of a conductive fixed cylindrical portion placed inside said fixed helical antenna, electromagnetically coupled therewith and electrically insulated therefrom, and a movable portion extending through an inside of said fixed cylindrical portion, said movable portion being slidably mounted to extend and retract in an axial direction, and wherein a proximal end of said movable portion is electrically connected to a distal end of said conductive fixed cylindrical portion when said movable portion of said rod antenna is in an extended position.

A portable radio apparatus comprising:

• an antenna assembly including:
• a helical antenna, and
• a rod antenna extending through an inside of said helical antenna in an axial direction thereof and being, slidably mounted to extend and retract in said axial direction, wherein said rod antenna includes a conductive portion, and wherein when in a retracted position a distal end of said conductive portion of said rod antenna is positioned below a proximal end of said helical antenna, and wherein when in an extended position a proximal end portion of said conductive portion of said rod antenna is electrically connected to a distal end of said helical antenna, thereby connecting said helical antenna and said rod antenna in series, and
• wherein said rod antenna further includes a non-metallic bar member having a length greater than an axial length of said helical antenna, and connected to said distal end of said conductive portion of said rod antenna so that said bar member is placed inside said helical antenna when said rod antenna is in said retracted position for electrically isolating said rod antenna from said helical antenna, and
• a helical antenna assembly includes a first helical antenna and a second helical antenna fixed to a distal end of said non-metallic bar member so that said second helical antenna is electrically isolated from said conductive portion of said rod antenna, and when said rod antenna is in said retracted position said distal end of said first helical antenna is electrically and directly connected via an antenna fixture to a proximal end of said second helical antenna, thereby connecting said first and second helical antennas in series to operate as said helical antenna assembly;
• a housing for supporting said antenna assembly and for retracting said rod antenna therein;
• and
• a power supply circuit for supplying power to said antenna assembly.

A portable radio apparatus comprising:

• an antenna assembly including:
• a fixed helical antenna including a first conductive terminal, and
• a rod antenna extending through an inside of said fixed helical antenna in an axial direction thereof and being slidably mounted to extend and retract in said axial direction, wherein said rod antenna is electrically isolated from said fixed helical antenna in both an extended position and a retracted position and includes:
• a conductive portion formed in a proximal portion of said rod antenna, wherein said conductive portion terminates in a second conductive terminal at a proximal end of said conductive portion of said rod antenna, and wherein when in a retracted position a distal end of said conductive portion of said rod antenna is positioned below a proximal end of said fixed helical antenna,
• a non-conductive bar member having a length greater than an axial length of said fixed helical antenna so that said non-conductive bar member is placed inside said fixed helical antenna when said rod antenna is in said retracted position for electrically isolating said rod antenna from said fixed helical antenna;
• and
• switching means for switching a power supply to one of said fixed helical antenna and said rod antenna in accordance with a position of said rod antenna;
• a housing for supporting said antenna assembly and for retracting said rod antenna therein;
• and
• a power supply circuit for supplying power to said antenna assembly.

A portable radio apparatus comprising:

• a fixed helical antenna formed in a cylindrical shape having a constant first diameter including first and second annular conductive terminals having a central aperture of a second diameter located respectively at distal and proximal ends thereof;
• a rod antenna extending through an inside of said fixed helical antenna in an axial direction thereof and being slidably mounted to extend and retract in said axial direction, wherein said rod antenna includes:
• a conductive portion formed in a proximal portion of said rod antenna, wherein said conductive portion terminates in a third conductive terminal of a length substantially equal to an axial length of said fixed helical antenna and having a diameter equal to said second diameter, and
• a non-conductive bar member formed in a distal portion of said rod antenna having a length greater than an axial length of said fixed helical antenna so that said non-conductive bar member is placed inside said fixed helical antenna when said rod antenna is in said retracted position for electrically isolating said rod antenna from said fixed helical antenna, wherein
• said first and second annular conductive terminals are electrically shorted by said third conductive terminal of said rod antenna and said third conductive terminal forms an environmental seal with said first conductive terminal when said rod antenna is in said extended position.

A portable radio apparatus comprising:

• an antenna assembly including:
• a fixed helical antenna, and
• a rod antenna positioned on a same axis as said helical antenna, wherein said rod antenna includes a conductive fixed cylindrical portion placed inside said fixed helical antenna, electromagnetically coupled therewith and electrically insulated therefrom, and a movable portion extending inside said fixed cylindrical portion, said movable portion being slidably mounted to extend and retract along said axis, and wherein a proximal end of said movable portion is electrically connected to a distal end of said conductive fixed cylindrical portion when said movable portion is in an extended position;
• a housing for supporting said antenna assembly and for retracting said rod antenna therein;
• and
• a power supply circuit for supplying power to said antenna assembly.