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Mobile Phone Patent Abstract
The mobile phone (1) has an antenna arrangement (5) for radiating
different radiation patterns (30, 35, 40) according to an actual
operation mode of the mobile phone (1). The different radiation
patterns include two radiation patterns that avoid introducing radiation
into the head of a user during an active telecommunications connection.
At least two operation modes of the mobile phone (1) are assigned
to a different radiation patern respectively. During an active operation
mode, the assigned radition pattern is selected and activated. A
change between the operation mode causes switching between the assigned
radiation patterns. In a preferred embodiment the radiation pattern
is omindirectional (30) during an idle mode, is directional (35)
during active telecomunications connections and is approximately
omindirectional with a preferential direction (40) during other
active telecommunications connections in which control signal are
exchanged.
Mobile Phone Patent Claims
What is claimed is:
1. A mobile phone (1) having plural operation modes, said plural
operation modes including an idle operation mode and a conversation
mode, wherein in said idle operation mode control signals are transmitted
to or received from a base station and an active telecommunication
connection is not established with the mobile phone and wherein
in said conversation mode said active telecommunication connection
is established with the mobile phone, said mobile phone comprising
(1): an antenna arrangement (5) consisting of at least one antenna
element (10,15; 95): means (70, 75) for supplying electrical energy
to said antenna arrangement so as to propagate radiation from said
at least one antenna element in a selected one of at lea two different
radiation patterns (30, 35, 40), wherein said at least two different
radiation patterns include an omnidirectional radiation pattern
(30) in which said radiation is propagated from the at least one
antenna element equally in all directions and a directional radiation
pattern (35) in which said radiation is propagated in one privileged
direction such that said radiation does not enter a head of a user
when the mobile phone is placed against an ear of the user; means
(20) for changing operation mode of the mobile phone between said
idle operation mode and said conversation mode; and means for controlling
said means for supplying electrical energy to said antenna arrangement
to select said selected one of said at least two different radiation
patterns propagated from said at least one antenna element, so as
to propagate said radiation during said idle operation mode in said
omnidirectional radiation pattern and during said conversation mode
in said directional radiation pattern with said one privileged direction,
so that said radiation is prevented from entering said head of said
user during said conversation mode.
2. The mobile phone as defined in claim 1, wherein said antenna
arrangement consists of a first antenna element (10) for radiating
said omnidirectional radiation pattern (30) and a second antenna
element (15) for radiating said directional radiation pattern (35)
with said one privileged direction: said means for supplying said
electrical energy to said antenna arrangement comprises a radio
frequency part (25); and said means for controlling comprises a
base band part (20), a first switch (45) connected between said
radio frequency part (25) and said first antenna element (10) and
a second switch (50) connected been said radio frequency part (25)
and said second antenna element (15), wherein said base band part
(20) controls said first switch and said second switch, so as to
connect said first antenna element (10), but not said second antenna
element, to said radio frequency part (25) during said idle operation
mode and said second antenna element (15), but not said first antenna
element, to said radio frequency part (25) during said conversation
mode.
3. The mobile phone as defined in claim 2, wherein said plural
operation modes include another operation mode (40) in which additional
control signals are transmitted during said active telecommunication
connection and wherein said base band part (20) controls said first
switch and said second switch so as to alternately connect said
first antenna element (10) and said second antenna element (15)
to said radio frequency part (25) during said another operation
mode so that said additional control signals are transmitted and
received during said active telecommunication connection.
4. The mobile phone as defined in claim 2, wherein said mobile
phone is in an on-hook state during said idle operation mode and
said mobile phone is in an off-hook state during said conversation
mode.
5. The mobile phone as defined in claim 1, wherein said antenna
arrangement consists of only one antenna element (95) for propagating
said omnidirectional radiation pattern (30) or said directional
radiation pattern (35) with said one privileged direction; said
means for supplying said electrical energy to said antenna arrangement
comprises a radio frequency part (25) connected with a first antenna
network (60) and a second antenna network (65); and said means for
controlling comprises a base band part (20) and a third switch (55),
said third switch connecting said radio frequency part (25) and
either said first antenna network (60) or said second antenna network
(65) with said only one antenna element (95), so that said radio
frequency part (25) and said first antenna network (50) are connected
to said only one antenna element (95) during said idle operation
mode and said radio frequency part (25) and said second antenna
network (65) are connected to said only one antenna element (95)
during said conversation mode.
6. The mobile phone as defined in claim 5, wherein said plural
operation modes include another operation mode (40) in which additional
control signals are transmitted during said active telecommunication
connection and wherein said base band part (20) controls said third
switch (55) so as to alternately connect said first antenna network
(60) and said second antenna network (65) to said only one antenna
element (95) during said another operation mode so that said additional
control signals are transmitted and received during said active
Mobile Phone Patent Description
BACKGROUND OF THE INVENTION
The present invention relates to a mobile phone. A mobile phone
including an antenna arrangement with an antenna element, which
is able to radiate in two different radiation patterns, has already
been described in German Patent application DE 197 23 331.
PRIOR ART
The invention proceeds from a mobile phone in accordance is with
the generic class of the independent patent claim.
It is already known from the not yet published German patent application
DE 197 23 331, that a mobile phone comprises an antenna arrangement
with an antenna element which is able to radiate in two different
radiation patterns.
SUMMARY OF THE INVENTION
It is an object of the present invention to provide an improved
mobile phone of the above-described type having a plurality of operation
modes, especially a mobile phone which avoids introducing radiation
into the head of a user during an active telecommunications connection.
According to the invention the mobile phone has plural operation
modes and comprises an antenna arrangement for propagating radiation
in a plurality of different radiation patterns Including at least
two radiation patterns that are formed to avoid introducing radiation
into a head of a user of the mobile phone when the phone is next
to the head during an active telecommunication connection, which
antenna arrangement includes one or more antenna elements; means
for assigning at least two of the plural operation modes to a respective
different radiation pattern; means for changing operation between
the operation modes; and means for selecting and activating an assigned
radiation pattern selected from the plurality of the different radiation
patterns when the corresponding operation mode is active.
The mobile phone according to the invention has the advantage that
at least two operation modes of the mobile phone are assigned to
a different radiation pattern, respectively, so that during an active
operation mode the assigned radiation pattern is selected and activated,
and a change between two operation modes causes switching between
the assigned radiation patterns. In this way the requirements for
the radiation patterns may be adapted to the actual operation mode
of the mobile phone. Thereby a compromise may be achieved between
the required antenna performance and the amount of radiation In
the head of the user depending on the actual operation mode. A more
flexible use of the mobile phone is therefore possible.
The features of the dependent patent claims enable further improvement
of the invention.
It is very advantageous if only one antenna element is provided
in a preferred embodiment of the antenna arrangement to realize
at least two different radiation patterns. In this way, the same
number of radiation patterns may be realized with fewer antenna
elements Therefore, material and costs may be saved as well as weight
of the mobile phone.
Another advantage consists in that the antenna arrangement is switchable
between an omnidirectional and a directional radiation pattern.
Therefore, it is possible to profit from the advantage of an omnidirectional
radiation pattern with for example good overall radiation performance
as well as from the advantage of a directional radiation pattern
with for example a prevention of high radiation in the head of the
user according to the requirements defined by the actual or activated
operation mode of the mobile phone.
Another advantage consists in that the first radiation pattern
is assigned to an idle operation mode during which the mobile phone
is not in a telecommunication connection, especially in an on-hook-state,
and transmitting control signals, and that second radiation pattern
is assigned to a first dedicated operation mode during which the
mobile phone is in an active telecommunication connection, especially
in an off-hook-state. On this way, a radiation pattern may be chosen
for the idle operation mode which allows good overall antenna performance,
because in the idle operation mode the mobile phone may be carried
inside a jacket or lying on a table and thereby preventing directional
radiation. In the dedicated operation mode a directional radiation
pattern may be chosen to prevent radiation into the head of the
user. Therefore, a good compromise between the performance of the
antenna arrangement and the prevention of radiation into the head
of the user dependent on the operation mode may be realized.
Another advantage consists in that the third radiation pattern
is assigned to a second dedicated operation mode during which the
mobile phone is transmitting control signals in an active telecommunication
connection, especially in an off-hook-state. On this way, a good
overall performance of the antenna arrangement may be chosen in
fractions of times when the mobile phone has to transmit control
signals to the corresponding base station in an active telecommunication
connection state. Thereby, it may be ensured that the control signals
reach the corresponding base station without allowing the radiation
into the head of the user during the times of the telecommunication
connection where no control signals has to be transmitted. This
would also represent a good compromise between telecommunication
requirements to keep up a telecommunication connection using the
transmission of control signals and the reduction of health risk
by minimizing the radiation into the head of the user.
BRIEF DESCRIPTION OF THE DRAWINGS
Examples of the invention are shown in the figures and explained
in greater detail in the description below.
FIG. 1 shows a block diagram of a first example of a mobile phone
according to the invention,
FIG. 2 shows a block diagram of a second example of a mobile phone
according to the invention,
FIG. 3 shows a combined radiation pattern, and
FIG. 4 shows an algorithm for a baseband part in the mobile phone
to select a radiation pattern.
DESCRIPTION
In FIG. 1 designates 1 a mobile phone comprising a baseband part
20 and a radio frequency part 25. The baseband part 20 is connected
to the radio frequency part 25. The radio frequency part 25 is connectable
via a first switch 45 to a first antenna element 10 providing a
first radiation pattern 30 which is an omnidirectional radiation
pattern. The radio frequency part 25 is connectable to a second
antenna element 15 via a second switch 50, the second antenna element
15 providing a second radiation pattern 35 which is a directional
radiation pattern. The radio frequency part 25, the first switch
45 and the second switch 50 are arranged in a first radio frequency
module 70. The first switch 45 is controlled via a first control
line 80 by the baseband part 20. The second switch 50 is controlled
via a second control line 85 by the baseband part 20. The first
antenna element 10 and the second antenna element 15 constitute
an antenna arrangement 5.
According to FIG. 1, the first switch 45 is closed and the second
switch 50 is open. Therefore, only the first antenna element 10
is connected to the radio frequency part 25.
Therefore, the omnidirectional radiation pattern 30 is selected
for the transmission of signals from the mobile phone 1. The omnidirectional
radiation pattern 30 is assigned to an idle operation mode during
which the mobile phone 1 is not in a telecommunication connection
as for example an active call. Thereby, the mobile phone 1 normally
is in an on-hook-state but may also be in an off-hook-state. In
the idle operation mode, the mobile phone 1 receives and/or transmits
control signals to a corresponding base station. As in the idle
operation mode, the mobile phone 1 normally is carried inside a
jacket or lying on a table for example, the antenna arrangement
5 is sufficiently distanced from the head of the user. Therefore,
radiation into the head of the user is essentially prevented in
the idle operation mode. To ensure the transmission of the control
signals to the corresponding base station the omnidirectional radiation
pattern 30 is assigned to the idle operation mode taking account
of disadvantageous radiation situations as described above for example
for the mobile phone 1 carried inside a jacket.
The directional radiation pattern 35 may be assigned to a first
dedicated operation mode during which the mobile phone 1 is in an
active telecommunication connection as for example an active call,
whereby the mobile phone 1 normally is in an off-hook-state. In
the case of a speech telecommunication connection, the first dedicated
operation mode may also be called a conversation mode. In conversation
mode, the user normally keeps the mobile phone 1 on an ear. Therefore,
radiation into the head of the user should be prevented and the
directional radiation pattern 35 is selected and assigned to the
first dedicated operation mode. Thereby, the radiation should be
directed away from the head of the user to minimize the power wasted
in his head.
According to FIG. 1 with the first switch 45 closed and the second
switch 50 open, the mobile phone 1 is in the idle operation mode.
If the user wants to make a call or receives a call, the operation
mode of the mobile phone 1 is changed from the idle operation mode
to the first dedicated operation mode. Thereby, the baseband part
20 controls via the first control line 80 the first switch 45 in
such a way, that the first switch 45 will be opened. The baseband
part 20 via the second control line 85 controls the second switch
50 in such a way, that the second switch 50 will be closed.
Then in the first dedicated operation mode, the second antenna
element 15 is connected to the radio frequency part 25, whereby
the first antenna element 10 is disconnected from the radio frequency
part 25. Thereby, the directional radiation pattern 35 is realized
for the first dedicated operation mode. On this way, the antenna
arrangement 5 is switched from the omnidirectional radiation pattern
30 to the directional radiation pattern 35. If the telecommunication
connection is finished, the operation mode of the mobile phone 1
changes from the first dedicated operation mode to the idle operation
mode and the baseband part 20 controls the first switch 45 via the
first control line 80 to be closed and the second switch 50 via
the second control line 85 to be opened. Therefore, the first antenna
element 10 will be reconnected to the radio frequency part 25 and
the second antenna element 15 will be disconnected from the radio
frequency part 25. In this case, the antenna arrangement 5 is switched
from the directional radiation pattern 35 to the omnidirectional
radiation pattern 30.
It is also possible to provide a third operation mode, for example
a second dedicated operation mode during which the mobile phone
is transmitting control signals in an active telecommunication connection
as for example an active call, whereby the mobile phone 1 normally
is in the off-hook-state. The transmission of the control signals
from the mobile phone 1 to the corresponding base station in an
active telecommunication connection is used to inform the corresponding
base station about the signal quality. Thereby, the control signals
are transmitted in fractions of times during the active telecommunication
connection. A third radiation pattern may be assigned to the second
dedicated operation mode. Thereby, the third radiation pattern may
correspond to the first radiation pattern 30 and therefore to the
omnidirectional radiation pattern of the first antenna element 10.
Therefore, it may be ensured, that the control signals, transmitted
from the mobile phone 1 in an active telecommunication connection,
reach the corresponding base station. On this way, in an active
telecommunication connection of the mobile phone 1 the first dedicated
operation mode changes to the second dedicated operation mode for
fraction of times. The baseband part 20 thereby controls via the
first control line 80 the first switch 45 and via the second control
line 85 the second switch 50 to connect the first antenna element
10 to the radio frequency part 25 and to disconnect the second antenna
element 15 from the radio frequency part 25 during the fractions
of time when the second dedicated operation mode is active and to
connect the second antenna element 15 to the radio frequency part
25 and to disconnect the first antenna element 10 from the radio
frequency part 25 when the first dedicated operation mode is active.
On this way, the omnidirectional radiation pattern 30 is selected
in an active telecommunication connection only during the fractions
of time for the transmission of the control signals, whereby the
radiation into the head of the user is minimized in an active telecommunication
connection.
To improve the signal quality for the transmission of the control
signals in the idle operation mode or in the second dedicated operation
mode, both antenna elements 10, 15 may be connected via the switches
45, 50 to the radio frequency part 25 during the idle operation
mode and the second dedicated operation mode. Supposing that the
two antenna elements 10, 15 are located close to each other, the
connection of both antenna elements 10, 15 to the radio frequency
part 25 via closed switches 45, 50 will result in a third radiation
pattern 40 which is as superposition of the omnidirectional radiation
pattern 30 and the directional radiation pattern 35. The third radiation
pattern in this case will be an omnidirectional radiation pattern
with one privileged direction as shown in FIG. 3. It is also possible,
to assign the third radiation pattern 40 to the idle operation mode
and the first radiation pattern 30 to the second dedicated operation
mode. Therefore, the radiation into the head of the user caused
by the second dedicated operation mode is kept at a minimum.
According to the example of FIG. 1, each antenna element 10, 15
provides exactly one radiation pattern 30, 35. According to FIG.
2, a second example of a mobile phone 1 according to the invention
is described whereby a third antenna element 95 is provided to realize
the first and the second radiation pattern 30, 35. In FIG. 2 the
baseband part 20 is also connected to the radio frequency part 25.
The third antenna element 95 constitutes the antenna arrangement
5. The third antenna element 95 is connectable via a third switch
55 either to a first antenna network 60 or to a second antenna network
65. The first antenna network 60 and the second antenna network
65 are connected to the radio frequency part 25. The radio frequency
part 25, the first antenna network 60, the second antenna network
65 and the third switch 55 constitute a second radio frequency module
75. The third switch 55 is controlled via a third control line 90
by the baseband part 20. Depending on the connection of the third
antenna element 95 to the first antenna network 60 or the second
antenna network 65, two different radiation patterns may be realized
by the antenna arrangement 5. If the third antenna element 95 is
connected via the third switch 55 to the first antenna network 60,
the first radiation pattern 30 is realized as an omnidirectional
radiation pattern. If the third antenna element 95 is connected
via the third switch 55 to the second antenna network 65, the second
radiation pattern 35 is realized as a directional radiation pattern.
Therefore, the same functionality as described according to FIG.
1 may be achieved with the mobile phone 1 according to FIG. 2 except
the combination or superposition of the first radiation pattern
30 and the second radiation pattern 35. In the idle operation mode
and in the second dedicated operation mode the baseband part 20
controls the third switch 55 via the third control line 90 to connect
the third antenna element 95 to the first antenna network 60 and
therefore ensuring the first radiation pattern 30 of the antenna
arrangement 5. In the first dedicated operation mode, the baseband
part 20 controls the third switch 55 via the third control line
90 to connect the third antenna element 95 to the second antenna
network 65, therefore ensuring the realization of the second radiation
pattern 35 by the antenna arrangement 5.
FIG. 4 shows an algorithm for the control of the radiation patterns
and the operation modes in the baseband part 20 of the mobile phone
1. The algorithm may be realized in the baseband part 20 by a program
running on a processor of the baseband part 20. The program starts
when the baseband part 20 detects the change of the actual operation
mode. This happens for example by user interaction via a keyboard
not shown in FIG. 1 and FIG. 2 of the mobile phone 1, whereby the
keyboard is connected to the baseband part 20. The user could for
example dial a telephone number on the keyboard to initiate an active
call and therefore an active telecommunication connection. The change
between the first dedicated operation mode and the second dedicated
operation mode may be initiated by the baseband part 20 itself according
to system requirements which are known or programmed in the baseband
part 20 of the mobile phone 1. If a new operation mode has to be
installed for the mobile phone 1, the baseband part 20 has to determine
this new operation mode. Therefore, at step 100 of the algorithm
shown in FIG. 4, the baseband part 20 determines if the new operation
mode is the idle operation mode for example after finishing an active
telecommunication connection. If this is the case, the algorithm
branches to step 105, otherwise it branches to step 110. At step
105 the baseband part 20 determines the radiation pattern required
for the idle operation mode and controls the first switch 45 and
the second switch 50 according to FIG. 1 or the third switch 55
according to FIG. 2 to realize the radiation pattern assigned to
the idle operation mode at the antenna arrangement 5 as described
above according to FIG. 1 and FIG. 2. Afterwards the program is
left. At step 110, the baseband part 20 determines if the first
dedicated operation mode is the new operation mode selected for
example by a dialed telephone number on the keyboard of the mobile
phone 1. If this is the case, the program branches to step 115,
otherwise it branches to step 120. At step 115 the baseband part
20 controls the first switch 45 and the second switch 50 according
to FIG. 1 or the third switch 55 according to FIG. 2 to realize
the radiation pattern assigned to the first dedicated operation
mode at the antenna arrangement 5. Afterwards, the program is left.
At step 120, the baseband part 20 determines if the second dedicated
operation mode is selected. If this is the case, the program branches
to step 125, otherwise the program is left. At step 125, the baseband
part 20 controls the first switch 45 and the second switch 50 according
to FIG. 1 or the third switch 55 according to FIG. 2 to realize
the radiation pattern assigned to the second dedicated operation
mode at the antenna arrangement 5. Afterwards the program is left.
The assignment of radiation patterns to operation modes is described
above only as an example and may be adapted according to the requirements
of the telecommunications system in which the mobile phone 1 is
used and according to appropriate health aspects. Every assignment
of radiation patterns to operation modes is possible.
It is also possible to provide more than two antennas with different
radiation patterns and to combine radiation patterns of more than
two antennas for example by superposition. There could be a look-up
table in the processor of the baseband part 20 in which each operation
mode is assigned to a radiation pattern which has to be realized
by the antenna arrangement 5.
It would also be possible to provide antenna elements or at least
one antenna element to realize exactly one radiation pattern and
at least one antenna element to realize at least two different radiation
patterns in one and the same antenna arrangement 5 connectable to
the radio frequency part 25. It may also be possible to provide
at least one antenna element to realize more than two different
radiation patterns.
The mobile phone 1 may be any terminal operating in any wireless
system.
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