Active solid-state devices (e.g. – transistors – solid-state diode – Housing or package – For high frequency device
Reexamination Certificate
2000-08-14
2004-06-22
Flynn, Nathan J. (Department: 2826)
Active solid-state devices (e.g., transistors, solid-state diode
Housing or package
For high frequency device
C257S664000, C257S760000, C333S247000
Reexamination Certificate
active
06753604
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a high frequency circuit module and a communication device such as a mobile wireless terminal and a pocket telephone employing the same.
2. Description of the Prior Art
The miniaturization and the enhancement of the efficiency of power of a high frequency circuit module used for a mobile wireless terminal, a pocket telephone and others in view of the mountability and talk time have been important objectives.
For a high frequency circuit module used for a communication device such as conventional type mobile wireless terminal and pocket telephone, the one using a single layer or multi-layer dielectric substrate is known.
An example of a high frequency circuit module using a single layer dielectric substrate is shown in the proceeding of the 1996 Institute IEIC Spring Conference C-86, “A Power Amplifier Using Single Layer Alumina Substrate with Thin-Film Resistors and Capacitors for North American Digital Phone System” (hereinafter called first conventional technique). According to the first conventional technique, a transmission line which is a distributed element, a lumped constant element such as a resistor, a capacitor and an inductor and a semiconductor element are formed on the same surface of a dielectric substrate to compose an input-output matching circuit and a power amplifier. A high frequency signal is transmitted to an external device by a high frequency signal electrode provided to the surface of the dielectric substrate. The earth electrode of the semiconductor element provided to the surface of the dielectric substrate and an earth electrode on the reverse side are connected via a through-hole.
Also, an example of a high frequency circuit module using a multi-layer (two-layer) dielectric substrate is shown in the proceeding of the 1997 Institute IEIC Conference Electronics Society C-2-14, “1.9 GHz RF Front-End Module Using a Ceramics Substrate” (hereinafter called second conventional technique). According to the second conventional technique, a transmission line which is a distributed constant element, an input-output matching circuit composed of a lumped constant element such as a resistor, a capacitor and an inductor and a semiconductor element are formed on the same surface of a dielectric substrate to compose a high frequency circuit module. A high frequency signal electrode provided to the surface of a first layer of the dielectric substrate and a high frequency signal electrode on the reverse side of a second layer are connected via wiring provided to the surface of the second layer through a through-hole. The earth electrode of the semiconductor element provided to the surface of the first layer of the dielectric substrate and an earth electrode on the reverse side are connected via a through-hole. The order of the layers of the dielectric substrate are counted as a first layer, a second layer, a third layer, etc., from the surface to the reverse side.
SUMMARY OF THE INVENTION
Referring to
FIGS. 9
to
11
, relationship between the miniaturization and the enhancement of the efficiency of power in the first conventional type technique will be described below.
FIG. 9
is a general schematic sectional view showing a transmission line formed on a single layer dielectric substrate. A conductor
43
on the surface, a dielectric substrate
44
and ground metal on the reverse side
45
forms a transmission line.
FIG. 10
shows calculated values of transmission loss at the frequency of 1.9 GHz when the relative dielectric constant of the dielectric substrate
44
is 8.1 and the thickness of the dielectric substrate
44
is varied from 0.1 mm to 3.0 mm. Curves
1
to
3
show cases in which the width of the conductor
43
forming a transmission line is respectively 0.1 mm, 0.2 mm and 0.5 mm. As clear from
FIG. 10
, in the cases of any width of the conductor
43
, as the dielectric substrate
44
becomes thick, the transmission loss has a tendency to become small.
FIG. 11
shows calculated values of transmission loss at the frequency of 1.9 GHz when the relative inductivity of the dielectric substrate
44
is 8.1 and the width of the conductor
43
forming a transmission line is varied from 0.02 mm to 3.0 mm. Curves
1
to
3
show cases in which the thickness of the dielectric substrate
44
is respectively 0.15 mm, 0.3 mm and 0.6 mm. As clear from
FIG. 11
, in the cases of any thickness of the dielectric substrate
44
, the transmission loss decreases as the conductor
43
forming a transmission line becomes wide, becomes minimum in a range in which the width of the conductor
43
is 0.3 to 0.7 mm and increases when the conductor
43
becomes wider.
As clear from the above description, to reduce transmission loss, it is required to thicken the dielectric substrate
44
and widen the conductor
43
and the miniaturization of the high frequency circuit module has a limit.
Next, referring to
FIGS. 12
to
14
, relationship between the miniaturization and the enhancement of the efficiency of power in the second conventional type technique will be described.
FIG. 12
is a general schematic sectional view showing a transmission line formed on a two-layer dielectric substrate. A conductor
46
, a dielectric substrate
47
, ground metal
48
on the reverse side and ground metal
49
on the surface forms a transmission line.
FIG. 13
shows calculated values of transmission loss at the frequency of 1.9 GHz when the relative dielectric constant of the dielectric substrate
47
is 8.1 and the thickness of the dielectric substrate
47
is varied from 0.1 mm to 3.0 mm. Curves
1
to
3
show cases in which the width of the conductor
46
forming a transmission line is respectively 0.1 mm, 0.2 mm and 0.5 mm. As clear from
FIG. 13
, in the cases of any width of the conductor
46
, as the dielectric substrate
47
becomes thick, the transmission loss becomes small.
FIG. 14
shows calculated values of transmission loss at the frequency of 1.9 GHz when the relative inductivity of the dielectric substrate
47
is 8.1 and the width of the conductor
46
forming a transmission line is varied from 0.02 mm to 3.0 mm. Curves
1
to
3
show cases in which the thickness of the dielectric substrate
47
is respectively 0.15 mm, 0.3 mm and 0.6 mm. As clear from
FIG. 14
, in the cases of any thickness of the dielectric substrate
47
, as the conductor
46
forming a transmission line becomes wide, the transmission loss has a tendency to become small.
As clear from the above description, to reduce transmission loss, it is required to thicken the dielectric substrate
47
and widen the conductor
46
and the miniaturization of the high frequency circuit module has a limit.
The object of this invention is to provide a high frequency circuit module which can be more miniaturized and a communication device using it.
To achieve the object, a high frequency circuit module according to this invention uses a two or more-layer dielectric substrate and the thickness of the dielectric substrate between a conductor forming the transmission line of a matching circuit on the side of input or output and ground metal is composed of two or more layers.
Specifically, to thicken a dielectric substrate that ranges between the conductor forming the transmission line of the matching circuit on the side of input or output and the ground metal, the ground metal provided to the dielectric substrate between them is formed in the shape in which a part is hollowed out so that a part opposite to the conductor is included.
As a required part can be thickened without varying the thickness of the whole dielectric substrate, the transmission loss can be reduced, and a high frequency circuit module and a communication device using it can be miniaturized.
The above-mentioned and others features and objects of this invention will become more apparent by reference to the following description taken in conjunction with the accompanying drawings.
REFERENCES:
patent: 4890155 (1989-12-01), Miyagawa et al.
patent: 5387888 (1995-02-01), Eda e
Hase Eiichi
Imai Shun
Flynn Nathan J.
Mattingly Stanger & Malur, P.C.
Renesas Technology Corp.
Sefer Ahmed N.
LandOfFree
High frequency circuit module and communication device does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with High frequency circuit module and communication device, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and High frequency circuit module and communication device will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-3352151