Mobile phone, analysis device included therein, and analysis method
View Patent ↗A mobile phone has an upper antenna at the top of a casing constituting a body and a lower antenna at the bottom of the casing. The mobile phone includes an influence-on-antenna evaluation unit for evaluating the influence of the ambient environment on each of the antennas by determining an input impedance (Z) of each antenna at predetermined time intervals during connection and by comparing the determined input impedance with a predetermined input-impedance reference value (Z 0 ). Transmission power corresponding to the amount of radio waves radiated is supplied to the antenna that is less affected by the ambient environment and transmission power is not supplied to the antenna that is more affected by the ambient environment.
1. A mobile phone comprising:
a casing that constitutes a body;
an upper antenna at the top of the casing;
a lower antenna at the bottom of the casing; and
an influence-on-antenna evaluation unit for evaluating the influence of the ambient environment on each of the antennas by determining an input impedance (Z) of each antenna at predetermined time intervals during connection and by comparing the determined input impedance with a predetermined input-impedance reference value (Z 0 ), wherein
transmission power corresponding to the amount of radio waves radiated is supplied to the antenna that is less affected by the ambient environment and transmission power is not supplied to the antenna that is more affected by the ambient environment, and wherein;
the variation is given by adding the square differences (|Z(ω i )−Z 0 (ω i )| 2 ) between input impedances (Z(ω i )) and input-impedance reference values (Z 0 (ω i )) at a plurality of frequency points ω i (i=1, 2, . . . N (an integer)) within a predetermined frequency band.
2. An analysis device included in the mobile phones, the mobile phone comprising:
a casing that constitutes a body;
an upper antenna at the top of the casing;
a lower antenna at the bottom of the casing; and
an influence-on-antenna evaluation unit for evaluating the influence of the ambient environment on each of the antennas by determining an input impedance (Z) of each antenna at predetermined time intervals during connection and by comparing the determined input impedance with a predetermined input-impedance reference value (Z 0 ), wherein
transmission power corresponding to the amount of radio waves radiated is supplied to the antenna that is less affected by the ambient environment and transmission power is not supplied to the antenna that is more affected by the ambient environment, wherein
the input-impedance reference value (Z 0 ) is the impedance of an antenna located in free space,
wherein the analysis comprises:
a free-space-impedance storage unit for storing in advance the input-impedance reference value (Z 0 ) of an antenna in free space;
an upper-impedance calculation unit for calculating the input impedance of the upper antenna during connection;
a lower-impedance calculation unit for calculating the input impedance of the lower antenna during connection;
an upper-impedance-variation calculation unit for calculating the square difference between the input impedance of the upper antenna and the input-impedance reference value in free space;
a lower-impedance-variation calculation unit for calculating the square difference between the input impedance of the lower antenna and the input-impedance reference value in free space;
a comparison unit for comparing an upper-impedance variation calculated by the upper-impedance-variation calculation unit with a lower-impedance variation calculated by the lower-impedance-variation calculation unit; and
a switch unit for switching on or off the upper antenna and the lower antenna, wherein the switch unit supplies power only to the lower antenna by transferring no power from a power amplifying unit to a feed unit in the upper antenna when the upper-impedance variation is greater than the lower-impedance variation based on the comparison result given by the comparison unit, and wherein
the switch unit supplies power only to the upper antenna by transferring no power from the power amplifying unit to the lower antenna when the lower-impedance variation is greater than the upper-impedance variation.
3. An analysis device according to claim 2 , wherein:
the upper antenna and the lower antenna are inverted L antennas.
4. An analysis device according to claim 2 , wherein:
the upper antenna and the lower antenna are helical antennas.
5. An analysis device according to claim 2 , wherein:
the upper antenna and the lower antenna are monopole antennas.
6. An analysis method of the mobile phone, the mobile phone comprising a casing that constitutes a body; an upper antenna at the top of the casing; a lower antenna at the bottom of the casing: and an influence-on-antenna evaluation unit for evaluating the influence of the ambient environment on each of the antennas by determining an input impedance (Z) of each antenna at predetermined time intervals during connection and by comparing the determined input impedance with a predetermined input-impedance reference value (Z 0 ), wherein transmission power corresponding to the amount of radio waves radiated is supplied to the antenna that is less affected by the ambient environment and transmission power is not supplied to the antenna that is more affected by the ambient environment, wherein the input-impedance reference value (Z 0 ) is the impedance of an antenna located in free space,
the method comprising:
a free-space-impedance storage step for storing the input-impedance reference value (Z 0 ) of an antenna in free space;
an upper-impedance calculation step for calculating the input impedance of the upper antenna during connection;
a lower-impedance calculation step for calculating the input impedance of the lower antenna during connection;
an upper-impedance-variation calculation step for calculating the square difference between the input impedance of the upper antenna and the input-impedance reference value in free space;
a lower-impedance-variation calculation step for calculating the square difference between the input impedance of the lower antenna and the input-impedance reference value in free space;
a comparison step for comparing an upper-impedance variation calculated by the upper-impedance-variation calculation step with a lower-impedance variation calculated by the lower-impedance-variation calculation step; and
a switching step for switching on or off the upper antenna and the lower antenna, and wherein
in the switching step, power is supplied only to the lower antenna by transferring no power from a power amplifying unit to a feed unit in the upper antenna when the upper-impedance variation is greater than the lower-impedance variation based on the comparison result given by the comparison step, and wherein
in the switching step, power is supplied only to the upper antenna by transferring no power from the power amplifying unit to the lower antenna when the lower-impedance variation is greater than the upper-impedance variation.
7. An analysis method of the mobile phone, according to claim 6 , wherein:
the upper antenna and the lower antenna are inverted L antennas.
8. An analysis method of the mobile phone, according to claim 6 , wherein:
the upper antenna and the lower antenna are helical antennas.
9. An analysis method of the mobile phone, according to claim 6 , wherein:
the upper antenna and the lower antenna are monopole antennas.