Antenna apparatus and portable radio apparatus

A portable radio apparatus comprising:

• an antenna including (i) a linear conductor that includes a first portion having a first physical length substantially equal to .lambda./4, where .lambda. is the wavelength of a signal frequency of interest, and a second portion having a second physical length substantially equal to n.lambda./2, where n is an integer, (ii) an insulator, and (iii) a rigid tubular conductor insulated from said linear conductor by said insulator and having a length substantially equal to said second physical length and being arranged coextensively with said second portion for covering only said second portion;
• a housing having grounding means for grounding said rigid tubular conductor of said antenna;
• and
• electric-circuit means electrically connected to said linear conductor at one end of said second portion of said linear conductor of said antenna.

An antenna apparatus comprising:

• a housing including grounding means;
• first and second connecting conductors being attached to said housing so as to be electrically insulated from each other;
• and
• an antenna slidably attached to said housing, including (i) a linear conductor that includes a first portion having a first physical length substantially equal to .lambda./4, where .lambda. is the wavelength of a signal frequency of interest, and a second portion having a second physical length substantially equal to n.lambda./2, where n is an integer, (ii) an end conductor connected to one end of said linear conductor on a side of said second portion, (iii) an insulator, and (iv) a rigid tubular conductor insulated from said end conductor and from said linear conductor by said insulator and having a length substantially equal to said second physical length and being arranged coextensively with said second portion for covering only said second portion,
• wherein said grounding means of said housing grounds said rigid tubular conductor, and said tubular conductor and said end conductor are engageable with said first and second connecting conductors, respectively, when said antenna is slidably pulled out of said housing.

A portable radio apparatus comprising:

• a housing including grounding means;
• first and second connecting conductors being attached to said housing so as to be electrically insulated from each other;
• an antenna slidably attached to said housing, including (i) a linear conductor that includes a first portion having a first physical length substantially equal to .lambda./4, where .lambda. is the wavelength of a signal frequency of interest, and a second portion having a second physical length substantially equal to n.lambda./2, where n is an integer, (ii) an end conductor connected to one end of said linear conductor on a side of said second portion, (iii) an insulator, and (iv) a rigid tubular conductor insulated from said end conductor and from said linear conductor by said insulator and having a length substantially equal to said second physical length and being arranged coextensively with said second portion for covering only said second portion;
• and
• electric-circuit means electrically connected to said end conductor of said antenna,
• wherein said grounding means of said housing grounds said rigid tubular conductor, and said tubular conductor and said end conductor are engageable with said first and second connecting conductors, respectively, when said antenna is slidably pulled out of said housing.

An antenna apparatus comprising:

• a housing including grounding means;
• first and second connecting conductors attached to said housing so as to be electrically insulated from each other;
• a linear antenna slidably attached to said housing, including (i) a linear conductor that includes a first portion having a first physical length substantially equal to .lambda./4, where .lambda. is the wavelength of a signal frequency of interest, and a second portion having a second physical length substantially equal to n.lambda./2, where n is an integer, (ii) an end conductor connected to one end of said linear conductor on a side of said second portion, (iii) an insulator, and (iv) a rigid tubular conductor insulated from said end conductor and from said linear conductor by said insulator and having a length substantially equal to said second physical length and being arranged coextensively with said second portion for covering only said second portion;
• and
• a helical antenna having a helical conductor insulated from said linear conductor of said linear antenna and coaxially disposed with said linear conductor,
• wherein said grounding means of said housing grounds said rigid tubular conductor, and said tubular conductor and said end conductor are engageable with said first and second connecting conductors, respectively, when said linear antenna is slidably pulled out of said housing, while said helical conductor is electrically connected to said second connecting conductor when said linear antenna is accommodated within said housing.

A portable radio apparatus comprising:

• a housing including grounding means;
• first and second connecting conductors attached to said housing so as to be electrically insulated from each other;
• a linear antenna slidably attached to said housing, including (i) a linear conductor that includes a first portion having a first physical length substantially equal to .lambda./4, where .lambda. is the wavelength of a signal frequency of interest, and a second portion having a second physical length substantially equal to n.lambda./2, where n is an integer, (ii) an end conductor connected to one end of said linear conductor on a side of said second portion, (iii) an insulator, and (iv) a rigid tubular conductor insulated from said end conductor and from said linear conductor by said insulator and having a length substantially equal to said second physical length and being arranged coextensively with said second portion for covering only said second portion;
• a helical antenna having a helical conductor insulated from said linear conductor of said linear antenna and coaxially disposed with said linear conductor;
• and
• electric-circuit means electrically connected to said end conductor of said linear antenna,
• wherein said grounding means of said housing grounds said rigid tubular conductor, and said tubular conductor and said end conductor are engageable with said first and second connecting conductors, respectively, when said linear antenna is slidably pulled out of said housing, while said helical conductor is electrically connected to said second connecting conductor when said linear antenna is slidably accommodated within said housing.