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Description
Title of Invention
USB CABLE ANTENNA
Technical Field
[0001]
The present disclosure relates to a USB cable antenna obtained by extending
the function of a USB (Universal Serial Bus) cable used for input/output of an
10 information terminal device.
Background Art
[0002]
To receive TV broadcasting by an information terminal device such as a
15 mobile phone, one of the method of providing a dedicated receiving antenna inside
the information terminal device and the method of capturing antenna input from an
earphone terminal to listen to an audio signal is generally used.
[0003]
There is also a desire to receive TV broadcasting in a room in which there is
20 no antenna receptacle for TV broadcasting such as a kitchen in the home. In such a
case, using a power transmission cable as an antenna for TV broadcasting is
proposed (see, for example, Patent Literature 1).
[0004]
According to the technology described in Patent Literature 1, the distance
25 between an inductor for high-frequency cutoff provided on the side of a power
supply circuit of a power transmission cable and an inductor for high-frequency
cutoff provided on the side of a mobile terminal is set to an integral multiple of the
1/4 wavelength of the carrier frequency of received TV broadcasting or the like.
Accordingly, TV broadcasting or the like in a wide frequency band can be received.
30 [0005]
Also, a receiving apparatus capable of obtaining sufficient antenna
10
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characteristics even if a connector is shared when a cable used as an antenna is
caused to transmit another signal whose frequency overlaps is proposed by the
present inventors (see Patent Literature 2).
Citation List
Patent Literature
[0006]
Patent Literature 1: JP 2010-15 7991A
Patent Literature 2: JP 2010-219904A
Summary of Invention
Technical Problem
[0007]
Under such circumstances, there is as much need to desire to listen to FM
15 radio or view TV on an information terminal device as in the past. However, with
an increasingly thinner and smaller size of information terminal devices in recent
years, there is a shortage of space in which many connectors are arranged.
Thus, if a USB cable used for signal transmission and power supply of all
information terminal devices can be used as an antenna to receive a radio wave of
20 television broadcasting or the like, the effect thereof is powerful.
[0008]
An object of the present disclosure is to provide a USB cable antenna
capable of receiving a radio wave of FM radio or TV by using a USB cable
connected to a USB terminal of an information terminal device and provided with an
25 antenna function of a high-frequency signal.
Solution to Problem '
[0009]
To solve the above issues, according to an embodiment of the present
30 disclosure, there is provided a USB cable antenna which also uses a USB cable as an
antenna that receives a high-frequency signal in a desired band, by connecting a
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metal shield of the USB cable to an ID terminal of a USB connector connected to the
USB cable of a predetermined length connected to an information terminal device,
connecting a high-frequency cutoff element having a high impedance for the highfrequency
signal in the desired band to both ends of a power supply line and a
5 ground line of the USB cable, and connecting a common mode choke having the
high impedance for the high-frequency signal in the desired band to both ends of a
transmission line of a differential signal of the USB cable.
[0010]
The high-frequency signal in the desired band received by the antenna is a
10 signal of one or a plurality of bands of a FM band, a VHF band, and a UHF band.
Advantageous Effects of Invention
[0011]
According to a USB cable antenna in the present disclosure, a USB cable
15 necessary for connecting an information terminal device and a host computer can be
used as a high-frequency antenna to receive television broadcasting or the like and
therefore, there is no need to provide a built-in antenna on the side of the information
terminal device. In addition, there is no need to provide a dedicated connector to
connect a receiving antenna of television broadcasting or the like on the side of the
20 information terminal device and therefore, further miniaturization and slimming
down of the information terminal device can be realized.
Brief Description of Drawings
[0012]
25 [FIG. 1] FIG. 1 is a schematic diagram showing an embodiment of a USB cable
antenna according to the present disclosure.
[FIGS. 2(A) to 2(D)] FIGS. 2(A) to 2(D) are diagrams showing concrete examples of
the USB cable antenna having an A-type USB connector connected to one end
thereof and a B-type USB connector connected to the other end thereof.
30 [FIGS. 3(A) and 3(B)] FIGS. 3(A) and 3(B) are diagrams showing eye patterns when
compliance tests of a differential signal of USB I.l and USB 2.0 are performed by
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setting the DC resistance of a ferrite bead (FB) inserted into a ground line to 1 Q and
the high-frequency resistance of a common mode choke inserted into a differential
signal line to 90 Q (100 MHz) in the USB cable antenna shown in FIG 2.
[FIGS. 4(A) and 4(B)] FIGS. 4(A) and 4(B) are diagrams showing eye patterns when
5 compliance tests of a differential signal of USB l.I and USB 2.0 are performed by
setting the DC resistance of a ferrite bead (FB) inserted into a ground line to 0.05 Q.
and the high-frequency resistance of a common mode choke inserted into a
differential signal line to 90 D. (100 MHz) in the USB cable antenna shown in FIG 2.
[FIGS. 3(A) and 3(B)] FIGS. 3(A) and 3(B) are diagrams showing eye patterns when
10 compliance tests of a differential signal of USB I.l and USB 2.0 are performed by
setting the DC resistance of a ferrite bead (FB) inserted into a ground line to 0.05 Q
and the high-frequency resistance of a common mode choke inserted into a
differential signal line to 120 Q (100 MHz) in the USB cable antenna shown in FIG
2.
15 [FIGS. 6(A) and 6(B)] FIGS. 6(A) and 6(B) are diagrams showing frequency-gain
characteristics when TV waves of the VHF band (A) and the UHF band (B) are
received using the USB cable antenna shown in FIG. 2.
[FIG. 7] FIG. 7 is a diagram showing the relationship between the frequency and
high-frequency impedance when a current is passed to the ferrite bead (FB) provided
20 in a power transmission line of the USB cable antenna.
[FIG 8] FIG. 8 is a diagram showing a concrete configuration of a USB-A connector
to which the USB cable connector is connected.
[FIG 9] FIG. 9 is a diagram (when a ferrite core is inserted) showing frequency-gain
characteristics when (A) no AC adapter is connected to the USB cable antenna and
25 (B) the AC adapter is connected to the USB cable antenna.
[FIG. 10] FIG 10 is a diagram (when a ferrite core is not inserted) showing
frequency-gain characteristics when (A) no AC adapter is connected to the USB
cable antenna and (B) the AC adapter is connected to the USB cable antenna.
30 Description of Embodiments
[0013]
^
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As described above, with further slimming down and miniaturization of
recent information terminal devices, it is becoming more difficult to secure a space to
provide an antenna needed to receive a radio wave of TV broadcasting on the side of
the information terminal device or a special connector connected to an external
5 antenna. For example, some earphone antennas have been proposed by inventors
and the like as an antenna to receive a radio wave of TV broadcasting. However,
the size of diameter of a terminal for earphone needed for the earphone antenna is
also an obstacle to further slim down the information terminal device.
[0014]
10 Thus, some thin information terminal devices in recent years are provided
with only a USB terminal without having any earphone terminal. Such information
terminal devices are charged from a host computer and various signals are
transmitted between the host computer and the information terminal devices by using
the USB cable.
15 [0015]
To solve the above problem, the inventors focused on a USB terminal
mounted on many information terminal devices and a USB cable connected thereto
and attempted various ideas and experiments by considering whether the USB cable
can be used as a receiving antenna of television broadcasting or the like. As a result,
20 as will be described below, the inventors devised a method of using a USB cable as
an antenna capable of receiving a radio wave of television broadcasting or the like.
[0016]
An embodiment (hereinafter, called the "present example") of a USB cable
antenna according to the present disclosure will be described below with reference to
25 FIGS. 1 to 10 and the description will be provided in the order shown below:
1. Schematic configuration of a USB cable antenna
2. Concrete example of the USB cable antenna '
3. Verification of maintenance of the USB cable function of the USB cable
antenna
30 4. Frequency-gain characteristics of the USB cable antenna
5. High-frequency impedance characteristics of FB inserted into a power
/I^R
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supply line of the USB cable antenna
6. Concrete example of the USB-A connector to which the USB cable
connector is connected
7. Characteristics comparison when an AC adapter is connected to the USB
5 cable antenna
[0017]

FIG. 1 is a diagram illustrating the configuration of a USB cable antenna in
the present example and the operation principle thereof. As shown in FIG. 1, a
10 female USB connector for USB cable connection is provided on the side of an
information terminal device (hereinafter, also called a "set")- The USB connector
provided on the set side will be called a "set-side USB connector 10" below.
[0018]
Then, a male B-type USB connector is attached to one end of a coaxial
15 shielding wire of an appropriate length (for example, about 95 to 115 cm).
Hereinafter, the male USB connector will be called a "cable-side USB-B connector
20" to distinguish from the set-side USB connector 10.
A male A-type USB connector is attached to the other end of the USB cable.
The USB connector will be called a "cable-side USB-A connector 30". The USB
20 connector is a standard-type USB connector and is connected to the host computer
side.
[0019]
First, the set-side USB connector 10 will be described with reference to FIG
1 and then a concrete connecting relation to the USB cable antenna in the present
25 example will be described.
In general, the set-side USB connector 10 (female type) and the cable-side
' USB-B connector 20 (male type) each have five connection pins and a shielding
terminal. A |j.USB-B connector is normally used as the set-side USB connector 10
and the cable-side USB-B connector 20. In contrast, the cable-side USB-A
30 connector 30 connected to the host computer side is a standard-type A-type USB
connector capable of supplying power.
I^Q
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In recent years, however, the distinction between the A type and the B type
has become blurry and an A-type or AB-type (USB connector used for both of the
host side and the set side) |aUSB connector may be used as the set-type USB
connector 10.
5 [0020]
As shown in FIG. 1, 1-pin of the set-side USB connector 10 is a Vbus/MIC
terminal for power supply and power is fed from the side of the host computer (not
shown) to the information terminal device (set) via 1-pin and also a voltage is
supplied to an earphone microphone or the like connected to the set. A ferrite bead
10 11 for high-frequency cutoff is connected in series to a line to which 1-pin of the setside
USB connector 10 is connected. Hereinafter, the ferrite bead may be
abbreviated simply as "FB".
[0021]
2-pin and 3-pin of the set-side USB connector 10 are terminals of a signal
15 line of differential signals to be transmitted and received through the USB cable, and
when an audio signal is input into these terminals, 2-pin (D- terminal) functions as a
terminal of an L channel and 3-pin (D+ terminal) functions as a terminal of an R
channel. A common mode choke 12 is connected to a line to which 2-pin and 3-pin
used for differential are connected. Then, high-frequency signals are cut off and
20 only an audio signal is passed by the common mode choke 12. In the description
that follows, the high-frequency signal may also be called an "RF signal" or "antenna
signal".
[0022]
4-pin of the set-side USB-B connector 10 is an ID terminal (ID is an
25 abbreviation of Identification, also called an "identification terminal") to identify the
type of an inserted plug and the use to which the plug is applied.
In the set-side USB connector 10 in the-present example, as shown in FIG. 1,
4-pin used as the ID terminal is used as an antenna terminal to receive TV
broadcasting or the like. Thus, a capacitor 14 of about 1000 pF is connected in
30 series to a line to which 4-pin is connected and an antenna signal supplied to 4-pin
via the capacitor 14 is supplied to a tuner circuit (not shown) in the set.
It
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[0023]
4-pin of the set-side USB-B connector 10 is a pin naturally used as a normal
ID terminal. High-frequency signals of television and the like can be an obstacle in
realizing the function as a normal ID terminal and an FB 13 as a high-frequency
5 cutoff element is connected in parallel with the capacitor 14 to the line'to which 4-
pin is connected to remove such high-frequency signals. Accordingly, an ID signal
from which high-frequency antenna signals such as a television signal have been
removed is output to an ID identification circuit (not shown) on the set side.
Incidentally, 5-pin of the set-side USB connector 10 is a ground terminal for
10 grounding and a line to which 5-pin is connected is connected and grounded to each
of external shields of the cable-side USB-B connector 20 and set described later.
[0024]
As described above, a substrate 22 is provided at one end of a coaxial
shielding wire 21 in the USB cable antenna shown in FIG. 1 and the male cable-side
15 USB-B connector 20 is connected to the substrate 22. Like the set-side USB
connector 10, a |j,USB connector is used normally for the cable-side USB-B
connector 20, but in addition, a |aUSB connector of the A type or AB type may also
be used.
[0025]
20 A resistor 23 is connected between the ID terminal (4-pin) of the cable-side
USB-B connector 20 and the ground line and based on the value of the resistor 23,
the USB connector of which use is connected and how the USB cable is used can be
known.
In addition, a metal shield 27 of the coaxial shielding wire 21 is connected
25 to the ID terminal and the metal shield 27 functions as a monopole antenna described
later.
[0026]
Also, an FB 24 as an element to cut off high-frequency signals is connected
to a power supply line to which 1-pin of the cable-side USB-B connector 20 shown
30 in FIG. 1 is connected. A common mode choke 25 is connected to 2-pin (Dterminal)
and 3-pin (D+ terminal) that transmit a differential signal. Like the
^
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common mode choke 12 provided in the set-side USB connector 10, the common
mode choke 25 also has a function to cut off high-frequency waves. Similarly, an
FB 26 as an element to cut off high-frequency waves is connected to the ground line
to which 5-pin of the cable-side USB- B connector 20.
5 [0027]
As shown in FIG. 1, the standard A-type cable-side USB-A connector 30 is
connected to the other end of the coaxial shielding wire 21. An FB 31 for cutting
off high-frequency waves is connected to 1-pin of the cable-side USB-A connector
30. A common mode choke 32 is connected to the signal line to which 2-pin and 3-
10 pin to which a differential signal is supplied are connected. Further, an FB 33 for
cutting off high-frequency waves is connected to the ground line to which 5-pin is
connected. To satisfy both of the ordinary USB cable signal function and the
antenna function of a high-frequency signal like a television signal, the DC resistance
of the FB 33 inserted into the ground line is desirably 0.25 Q or less. As the
15 common mode choke 32, for example, a product having 90 Q. for high-frequency
waves or a product having 120 Q is used.
[0028]
In the USB cable antenna in the present example, the metal shield 27 as a
skin conductor of the coaxial shielding wire 21 is connected to the ID terminal (4-
20 pin) of the cable-side USB-B connector 20. As shown in FIG. 1, the metal shield 27
connected to the ID terminal is a shielding line that is different from the ground line.
[0029]
The reason why the metal shield 27 is connected to the ID terminal (4-pin)
to receive a radio wave like a television signal is as follows:
25 The transfer clock used for signal transfer in USB 2.0 is fixed to 480 Mbps.
A signal of the transfer clock operates between the differential signal line and the
ground line and thus, if the ground line of a USB cable is used as an antenna of a
television signal, the antenna is in a state in which the clock signal of 480 Mbps of
USB is superimposed on a RF signal of television or the like. The so-called
30 "fogging" occurs.
[0030]
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Therefore, when a USB cable is used as an antenna for television
broadcasting, the ground line cannot be used as an antenna. As a result of
experiment, the inventors found that the problem can be solved by using the metal
shield 27 that is different from the ground line.
5 Incidentally, the clock of 480 Mbps in USB 2.0 corresponds to a frequency
of 240 MHz and thus, the band particularly affected adversely is the VHF-H (high)
band.
[0031]
When the male cable-side USB-B connector 20 is inserted into the female
10 set-side USB-B connector 10, it is necessary to discriminate (detect) whether an
antenna capable of receiving a radio wave of television broadcasting or the like is
inserted. Thus, the resistor 23 is inserted between the line to which the ID terminal
(4-pin) of the cable-side USB-B connector 20 and the ground line to which 5-pin is
connected. The value of resistance of the resistor 23 is different depending on the
15 type of the cable-side USB-B connector 20, in other words, what the cable-side USBB
connector 20 is used for.
Therefore, by detecting the value (value of resistance) of the resistor 23,
whether a USB connector having an antenna function of television broadcasting or
the like is inserted can be detected.
20 [0032]
The value of resistance of the resistor 23 is normally high impedance
(hundreds of kD.) and thus, the ID line and the ground line are open at high
frequencies and antenna characteristics are not affected from the ground line to the
ID line. However, to be noted is a case of high-frequency connection by a capacitor
25 of connection capacity or the like after passing FB 64 to 67 connected to each line
other than the ID line. In such a case, a high-frequency current flows to each
terminal, causing the degradation of antenna characteristics.
[0033]

30 FIGS. 2(A) to 2(D) show samples of the above USB cable antenna. FIG
2(A) is a plan view when viewed from above, FIG. 2(B) is a sectional view of the B#
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type cable-side USB-B connector 20 (here, a |aUSB-B connector), FIG 2(C) is a
sectional view of the A-type cable-side USB-A connector 30 (here, a standard-type
USB-A connector), and FIG. 2(D) is a front view. The dimension of each figure is
based on the standard of the USB connector and |a.USB connector. In FIGS. 2(A) to
5 2(D), the same reference signs are attached to the same members as those in FIG 1.
[0034]
As shown in FIG. 2, the narrower side of the cable-side USB-B connector 20
has a width of 7 mm, which is suitable as a connection terminal of a mobile phone or
the like proceeding toward further slimming down in the future. On the other hand,
10 the narrower side in the section of the cable-side USB-A connector 30 connected to
the host computer has a width of 7.8 mm.
[0035]
In the Japanese television broadcasting, the VHF band of 90 to 108 MHz (1
to 3 ch) and 170 to 222 MHz (4 to 12 ch) and the UHF band of 470 to 770 MHz (13
15 to 62 ch) are used. Incidentally, the VHF band may be divided to call 90 to 108
MHz as the VHF-L (low) band and 170 to 222 MHz as the VHF-H (high) band. In
the USB cable antenna in the present example, the length of the cable is adjusted to
115 cm, which is about 3/4 the wavelength (3/4-A,) of 200 MHz so as to be able of
receive both of the VHF-H (high) band and the UHF band. Incidentally, UHF is
20 received by high-frequency excitation.
[0036]

When a television signal is received by connecting the cable-side USB-B
25 connector 20 of the above USB cable antenna in the present example to the set-side
USB connector 10, whether the original USB function is maintained is important.
Thus, a compliance test to verify whether the function of USB is degraded in the
USB cable antenna of the present example was performed. FIGS. 3(A) to 5(B) are
diagrams showing eye patterns of the compliance test to check whether the USB
30 cable antenna in the present example satisfies two standards of USB 1.1 and USB 2.0.
[0037]
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FIGS. 3(A) and 3(B) shows results of the compliance test of USB by setting
the DC resistance of the FB 26, 33 of the ground line to 1 Q and the common mode
chokes 25, 32 connected to the D- line and D+ line that transmit a differential signal
to 90 Q (100 MHz) in the USB cable antenna shown in FIG 2. FIG 3(A) shows an
5 eye pattern 40a of the compliance test of USB 1.1 and FIG 3(B) shows an eye
pattern 40b of the compliance test of USB 2.0.
[0038]
The eye pattern is also called an eye diagram or an eye opening ratio and is
created by sampling and superimposing the transition of a signal waveform many
10 times and graphically showing the result. The horizontal axis represents the time
and the vertical axis represents the vohage. If the eye pattern is viewed and a
plurality of signal waveforms is superimposed in the same position (timing and
voltage), the waveform is considered to be a high-quality waveform and conversely,
if positions (timing and voltage) of signal waveforms are shifted and signal
15 waveforms overlap with a hexagonal shape (template) in the center, the waveform is
considered to be a low-quality waveform. It is also known that a waveform of
degraded transmission characteristics has a hexagonal shape (template 43) in the
center that is thin and flat and the area thereof is small. The test is called an eye
pattern test (or an eye diagram test) because the relation between the signal lines and
20 the template is similar to the shape of an open human eye.
[0039]
The eye pattern 40a shows the compliance test result of USB 1.1 when the
DC resistance of FB inserted into the ground line is 1 Q and the impedance of the
common mode choke at 100 MHz is 90 Q. In the compliance test of USB 1.1,
25 differential signals 41a, 42a passing through the signal lines of D+ = 0.35 V and D- =
-0.35 V and having a phase difference of 180° are simultaneously displayed.
Viewing the displayed eye pattern 40a shows that a portion of waveforms of the
differential signal 41a or 42a overlaps with a template 43a in the hexagonal shape.
From the above result, the USB cable antenna in the present example does not satisfy
30 the function of USB 1.1, that is, the USB cable antenna failed (NG) in the
compliance test of USB 1.1.
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[0040]
On the other hand, the eye pattern 40b in FIG. 3(B) shows the compliance
test resuh of USB 2.0 when the DC resistance of FB inserted into the ground line is 1
Q and the impedance of the common mode choke at 100 MHz is 90 Q. In the
5 compliance test of USB 2.0, differential signals 41b, 42b passing through the signal
lines of D+ = 0.4 V and D- = -0.4 V and having a phase difference of 180° are
simultaneously displayed. Viewing FIG. 3(B) shows that differential signals 41, 42
propagated through the line to which 2-pin and 3-pin are connected are positioned
between parallel lines of D+ = 0.4 V, D- = -0.4 V and further, the hexagonal template
10 43 is positioned inside a region surrounded by these two differential signals 41, 42.
[0041]
That is, as far as USB 2.0 is concerned, FIG. 3(B) shows that even if 4-pin
of the USB connector to which a cable is connected is used also as an antenna input
terminal, the eye pattern test is passed, in other words, standards of USB 2.0 are
15 satisfied. In the standards of USB 2.0, the clock of transmission of a USB signal is
480 Mbps and belongs to the VHF band (240 MHz) as a frequency band.
[0042]
FIGS. 4(A) and 4(B) show eye patterns 50a, 50b showing results of
performing the compliance test of differential signals of USB 1.1 and USB 2.0 using
20 the USB cable antenna shown in FIG. 2. FIGS. 4(A) and 4(B) are different from
FIGS. 3(A) and 3(B) in that the DC resistance of the FB 26, 33 inserted into the
ground line is set to 0.05 Q. The impedance of the common mode chokes 25, 32 at
100 MHz remains 90 Q.
[0043]
25 In the eye pattern 50a, as shown in FIG. 4(A), all differential signal lines 51a,
52a of D+ and D- surround an eye pattern 53a. Also in the eye pattern 50b shown
in FIG 4(B), differential signal lines 51b, 52b of differential signal lines D+ and Dsurround
an eye pattern 53b and do not overlap with each other. The result means
that the USB cable antenna passes the compliance tests of USB 1.1 and USB 2.0, that
30 is, the standards of both of USB 1.1 and USB 2.0 are satisfied.
[0044]
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FIGS. 5(A) and 5(B) also show eye pattern diagrams showing compliance
test results of the USB cable antenna shown in FIG 2. FIGS. 5(A) and 5(B) are
different from FIGS. 4(A) and 4(B) in that a product whose impedance at 100 MHz
is 120 Q is used as the common mode choke 25, 32 inserted into the differential
5 signal lines. The DC resistance of the FB 26, 33 of the ground line remains the
same resistance of 0.05 Q as in FIG 4.
In the compliance test of USB 1.1 shown in FIG. 5(A), all differential signal
lines 61a, 62a of D+ and D- surround an eye pattern 63a and also in the compliance
test of USB 2.0 shown in FIG. 5(B), all differential signal lines 61b, 62b of D+ and
10 D- are similarly outside an eye pattern 63b and do not overlap with each other.
[0045]
From the above results, it is verified that a USB cable antenna satisfying
both standards of USB 1.1 and USB 2.0 can be obtained by appropriately selecting
the DC resistance of the FB 26, 33 inserted into the ground line and the impedance of
15 the common mode chokes 25, 32 inserted into the differential signal lines.
[0046]

The USB cable antenna in the present example shown in FIGS. 1 and 2
constitutes, as described above, a monopole antenna between the set and the ground
20 (GND). An experiment of receiving radio waves of television broadcasting in the
VHF-H band and the UHF band using the USB cable antenna was conducted. That
is, a sample of the USB cable antenna shown in FIG. 2 is connected to the female setside
USB connector 10 (see FIG. 1) to investigate transmission characteristics of a
high-frequency signal such as a television wave.
25 [0047]
Table 1 and FIG 6(A) show frequency-gain characteristics when television
broadcasting in the VHF band is received -by the USB cable antenna shown in FIG. 1.
In the VHF band of 170 to 220 MHz, as shown in Table 1 and FIG 6(A),
gain characteristics of-5 dB (-4.04 dB at 210 MHz) or more are exhibited in vertical
30 polarization and gain characteristics of -20 dB (-17.24 dB at 210 MHz) or more are
exhibited in horizontal polarization (see Table 1).
15/26
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[0048]
10
[Table 1]
Frequency [MHz]
Peak [dBd]
188.5
-3.27
192.5
-2.89
Vertical poiaiization
194.5
-2.97
198
-3.10
204
-3.40
210
-4.04
216
-4.68
222
-4.24
Frequency [MHz]
Peak [dBd]
188.5
-15.67
192.5
-15.49
Horizontal poiaiization
194.5
-15.37
198
-15,30
204
-16.00
210 -
-17.24
216
-18.08
222
-17.90
[0049]
Table 2 and FIG 6(B) show frequency-gain characteristics when television
broadcasting in the UHF band is received and in the UHF band of 470 to 870 MHz,
as shown in FIG. 6(B), gain characteristics of-12 dB or more are exhibited in vertical
polarization and gain characteristics of -8 dB or more are exhibited in horizontal
polarization.
These results show that the USB cable antenna shown in FIGS. 1 and 2
sufficiently fulfills the function as an antenna of the VHF-H band and the UHF band
of television broadcasting. These results mean that the USB cable antenna is also
applicable as an antenna for multimedia broadcasting planned to be broadcast using
the VHF band.
[0050]
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SP331470WO00
[Table 2]
Frequency [MHz]
Peak [dBd]
Frequency [MHz]
Peak [dBd]
470
-8.80
470
-5.00
520
-10.09
520
-4.29
Vertical polarization
570
-9.53
620
-11.61
670
-10.36
720
-3.18
Horizontal polarization
570
-1.64
620
-7.34
670
-5.96
720
-5.15
770
-7.85
770
-5.25
906
-3.98
906
-2.58
[0051]

5 Next, the FB 24, 31 connected to a power supply line (Vbus line) shown in
FIG. 1 will further be described. In contrast to the FB 26, 33 connected to the
ground line, the FB 24, 31 are special ferrite beads (FB) capable of maintaining highfrequency
characteristics even if a current flows.
The FB normally used like the FB 26, 33 inserted into the ground line has a
10 magnetic material around a coil and removes a high-frequency current by converting
the high-frequency current into heat using a high impedance state at high frequencies,
that is, a state of high high-frequency losses. That is, the FB plays the role as a
high-frequency signal cutoff element.
[0052]
15 The normal FB 26, 33 described above are produced while a coil is inside a
magnetic material and thus, the magnetic material is saturated when the current
increases. That is, in the normal FB, a closed magnetic circuit is formed and
magnetic fluxes are confined and thus, saturation is more likely to be reached when a
large current flows. Therefore, it becomes more difficult to maintain original
20 characteristics.
In contrast, the FB 24, 31 provided in the line for power supply to which 1-
pin of a USB terminal is connected are produced by taking a case when a large
%
SP331470WO00
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current flows into consideration and an open magnetic circuit is formed by a coil and
a magnetic material. Thus, magnetic fluxes are not confined even if a magnetic
material is present and therefore, even if a large current flows to the coil, the current
is converted into heat only inside the coil and the magnetic material is structured to
5 be less likely to be saturated.
[0053]
FIG 7 shows high-frequency impedance characteristics of the FB 24, 31
when a current is stepwise passed to a line to which the Vbus/MIC terminal (1-pin)
of the USB cable antenna is connected.
10 As is evident from FIG. 7, approximately the same frequency characteristics
are exhibited when no current is passed to the line to which 1-pin is connected (0
mA) and when currents are passed (100 mA, 300 mA, 500 mA, 700 mA). However,
as shown in FIG 7, it is verified that a little different frequency characteristics are
exhibited when the magnitude of the current is 1 A (1000 mA).
15 [0054]
It also turned out that insertion losses are about -20 dB to -27.5 dB in the
band of 200 MHz to 700 MHz corresponding to the VHF band to the UHF band of
television broadcasting.
Such a level of insertion losses can be considered to be a level allowing
20 reception of the VHF band to the UHF band of television broadcasting.
[0055]

Next, a concrete example of the USB-A connector to which the USB cable
25 antenna is connected will be described with reference to FIG 8.
The dotted line in the center of FIG 8 shows a substrate 70 and the left side
of the substrate 70 shows a USB-A plug inserted into the host. The right side of the
substrate 70 shows a connector portion to which the USB cable antenna in the
present example is connected.
30 In the USB-A plug on the left side of the substrate 30, socket pins are
arranged in a portion surrounded by a thick dotted line. That is, 1-pin 71 to which
SP331470WO00
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the power supply line (Vbus) is connected, 2-pin 72 to which the D- line of a
differential signal is connected, 3-pin 73 to which similarly the D+ line is connected,
and a socket pin of 4-pin 74 as the ID terminal are arranged in parallel from below.
5-pin 75 to which the ground line (GND) is connected is arranged above the 4-pin 74.
5 [0056]
The right side of the substrate 70 is a portion to which the USB cable
antenna of the present example is connected. 1-pin 71a to which a line of Vbus is
connected, 2-pin 72a and 3-pin 73a to which lines of differential signals D-, D+ are
connected respectively, and 4-pin 74a to which a line of GND is connected are
10 arranged from below. 5-pin 75a to which the metal shield 27 shown in FIG 1 is
connected is provided above the 4-pin 74a. The metal shield 27 connected to the 5-
pin 75a fulfills, as described above, the function as an antenna by being connected to
4-pin (ID terminal) of the set-side USB connector 10 (fxUSB-B connector) in FIG. 1.
[0057]
15 The 1-pin 71a on the right side of the substrate 70 is connected to the 1-pin
71 of the USB-A plug on the left side of the substrate 70 via the FB 31 and the 2-pin
72a and the 3-pin 73a on the right side of the substrate 70 are connected to the 2-pin
72 and the 3-pin 73 of the USB-A plug on the left side of the substrate 70 via the
common mode choke 32. The 4-pin 74a to which the GND line is connected on the
20 right side of the substrate 70 is connected to the 5-pin 75 as the GND terminal on the
left side of the substrate 70.
The 5-pin 75a to which the metal shield 27 of the USB cable antenna is
connected on the right side of the substrate 70 is not connected to any terminal on the
left side of the substrate 70 and is in an open state.
25 [0058]
In general, a USB-A connector provided at one end of the USB cable
antenna in the present example is connected to the host side including a power unit
and so is more likely to be affected by noise generated by the power unit. Thus, in
FIG. 8, pins are arranged on a straight line to make respective signal lines parallel so
30 as to be less likely to be affected by noise from the unit. Accordingly, a USB cable
antenna having the function as an antenna and less likely to be affected by noise from
SP331470WO00
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the power unit can be produced.
[0059]

5 If a charger (AC adapter) for USB is connected to the tip of a USB-A
connector, the USB cable antenna in the present example can receive a television
signal while being charged. Thus, an experiment to investigate to which extent
frequency-gain characteristics of the USB cable antenna change when an AC adapter
is connected to the tip of the USB-A connector and no AC adapter is connected was
10 conducted.
[0060]
Table 3, Table 4, and FIGS. 9(A) and 9(B) show frequency-gain
characteristics in the VHF band of the USB cable antenna in the present example
when no AC adapter is connected to the USB-A connector side to which the USB
15 cable antenna is connected (A) and an AC adapter is connected (B). In the
examples shown in FIGS. 9(A) and 9(B), a ferrite core (not shown) is arranged near
the USB-A plug and the USB antenna cable wound around the ferrite core once or
twice before making measurements.
It is clear from FIGS. 9(A) and 9(B) that if the ferrite core is inserted,
20 changes of frequency-gain characteristics are small when the USB-A plug is not
connected to the AC adapter (A) and the USB-A plug is connected to the AC adapter
(B).
[0061]
That is, viewing FIGS. 9(A) and 9(B) shows that near 210 MHz used for the
25 USB cable antenna, frequency-gain characteristics hardly change when the USB
cable antenna is not connected to the AC adapter in FIG. 9(A) (-26.06 dBd in vertical
polarization and -7.84 Bd in horizontal polarization) -and the USB cable antenna is
connected to the AC adapter in FIG. 9(B) (-25,95 dBd in vertical polarization and -
7.75 dBd in horizontal polarization) (see Table 3 and Table 4).
30 [0062]
20/26
SP331470WO00
[Table 3]
Frequency [MHz]
Peak [dBd]
188.5
-26.01
Frequency [KIHz]
Peak [dBd]
188.5
-10.17
[0063]
Frequency [MHz]
Peak [dBd]
188.5
-26.81
Frequency [KIHz]
Peak [dBd]
188.5
-10.72
Vertical polarization
192.5
-25.15
194.5
-25.49
198
-25.28
204
-25.40
210
-26.06
Horizontal polarization
192.5
-8.95
194.5
-8.61
198
-7.86
204
-7.40
210
-7.84
[Table 4]
Vertical polarization
192.5
-26.69
194.5
-26.21
198
-26.23
204
-26.00
210
-25.95
Horizontal polarization
192.5
-9.72
194.5
-9.41
198
-8.66
204
-7.84
210
-7.75
216
-27.13
216
-8.70
216
-28.15
216
-7.90
222
-26.21
222
-9.19
222
-25.21
222
-7.99
[0064]
5 Table 5, Table 6, and FIGS. 10(A) and 10(B) show changes of frequencygain
characteristics when no ferrite core is used. Like in FIGS. 9(A) and 9(B), FIG
10(A) shows a case when the USB cable antenna is not connected to the AC adapter
and FIG. 10(B) shows a case when the USB cable antenna is connected to the AC
adapter. Comparison of gains near 210 MHz in FIGS. 10(A) and 10(B) shows that
10 while the gain is -26.75 dB in vertical polarization (see Table 5) and -8.15 dB in
vertical polarization (see Table 5) when the AC adapter is present, the gain is -23.26
dB in vertical polarization (see Table 6) and -5.66 dB in vertical polarization (see
Table 6) when no AC adapter is inserted.
SP331470WO00
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The above results show that when television broadcasting in the VHP band
is received, inserting a ferrite core on the side of the USB-A connector is effective in
receiving a television signal in the VHF-H band regardless of whether or not an AC
adapter is present.
[0065]
[Table 5]
Frequency [Nfflz]
Peak [dBd]
Vertical polarization
188.5
-26.81
192.5
-26.45
194.5
-26.21
198
-25.43
204
-24.49
210
-23.26
216
-21.63
222
-21.61
Frequency [MHz]
Peak [dBd]
Horizontal polarization
188.5
-12.47
192.5
-11.52
194.5
-10.93
198
-10.06
204
-7.77
210
-5.66
216
-4.10
222
-4.75
[0066]
[Tible 6]
Frequency [MHz]
Peak [dBd]
188.5
-25.81
Vertical polarization
192.5
-25.65
194.5
-25.77
198
-25.73
204
-26.15
210
-26.75
216
-28.75
222
-29.37
Frequency [MHz]
Peak [dBd]
Horizontal polaiization
188.5
-9.67
192.5
-9.09
194.5
-8.81
198
-8.48
204
-8.20
210
-8.15
216
-9.33
222
-9.24
[0067]
10 In the foregoing, the USB cable antenna has been described as an
embodiment of the present disclosure. A USB cable antenna according to the
present disclosure naturally includes, in addition to the embodiment disclosed herein,
various application examples and modifications without deviating from the spirit and
SP331470WO00
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scope of the present disclosure described in claims.
[0068]
Additionally, the present technology may also be configured as below.
(I) A USB cable antenna which also uses a USB cable as an antenna that
5 receives a high-frequency signal in a desired band,
by connecting a metal shield of the USB cable to an ID terminal of a USB
connector connected to the USB cable of a predetermined length connected to an
information terminal device,
connecting a high-frequency cutoff element having a high impedance for the
10 high-frequency signal in the desired band to both ends of a power supply line and a
ground line of the USB cable,
and connecting a common mode choke having the high impedance for the
high-frequency signal in the desired band to both ends of a transmission line of a
differential signal of the USB cable.
15 (2) The USB cable antenna according to (1),
wherein the high-frequency signal in the desired band received by the
antenna is a signal of one or a plurality of bands of a FM band, a VHF band, and a
UHF band.
(3) The USB cable antenna according to (1) or (2),
20 wherein a resistor to identify a type of the USB cable connected to the ID
terminal is connected between an ID line to which the ID terminal is cormected and
the ground line of the USB cable. -.^ . ,.
(4) The USB cable antenna according to any one of (1) to (3),
wherein the high-frequency cutoff element inserted into the power supply
25 line has the high impedance also when a current flows to the power supply line.
(5) The USB cable antenna according to any one of (1) to (4),
wherein a DC resistance of the high-frequency cutoff element inserted into •
the ground line is 0.25 Q or less.
(6) The USB cable antenna according to any one of (1) to (5),
30 wherein the impedance in the desired band of the common mode choke
inserted into both ends of D- and D+ differential signal lines of the USB cable is 90
SP331470WO00
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Q, or more.
Reference Signs List
[0069]
5 21 coaxial shielding wire
10 set-side usb connector
20 cable-side usb-b connector
30 cable-side usb-a connector
11,13,26,33 ferrite bead (fb)
10 12, 25, 32 common mode choke
24, 31 ferrite bead (fb: for power supply line)
14 capacitor
23 resistor
27 metal shield
15 40a, 40b, 50a, 50b, 60a, 60b eye pattern
41a,42a,41b, 42b, 51a, 52a, 51b, 52b, 61a, 62a,61b, 62b d- or d+ differential
signal
43a, 43b, 53a, 53b, 63a, 63b template

ORIGINAL
SP331470WO00
24/26 196 7 pmp CLAIMS,
Claim 1
A USB cable antenna which also uses a USB cable as an antenna that
receives a high-frequency signal in a desired band,
5 by connecting a metal shield of the USB cable to an ID terminal of a USB
connector connected to the USB cable of a predetermined length connected to an
information terminal device,
connecting a high-frequency cutoff element having a high impedance for the
high-frequency signal in the desired band to both ends of a power supply line and a
10 ground line of the USB cable,
and connecting a common mode choke having the high impedance for the
high-frequency signal in the desired band to both ends of a transmission line of a
differential signal of the USB cable.
15 Claim 2
The USB cable antenna according to claim 1,
wherein the high-frequency signal in the desired band received by the
antenna is a signal of one or a plurality of bands of a FM band, a VHF band, and a
UHF band.
20
Claim 3
The USB cable antenna according to claim 2,
wherein a resistor to identify a type of the USB cable connected to the ID
terminal is connected between an ID line to which the ID terminal is connected and
25 the ground line of the USB cable.
Claim 4
The USB cable antenna according to claim 3,
wherein the high-frequency cutoff element inserted into the power supply
30 line has the high impedance also when a current flows to the power supply line.
t QPJGINAL
25/26 •<9g75mi3.
1 1 NOV 2015
Claim 5
The USB cable antenna according to claim 4,
wherein a DC resistance of the high-frequency cutoff element inserted into
the ground line is 0.25 Q. or less. '
Claim 6
The USB cable antenna according to claim 1,
wherein the impedance in the desired band of the common mode choke
inserted into both ends of D- and D+ differential signal lines of the USB cable is 90
10 Q. or more.