JPH01279612A - High frequency amplification circuit - Google Patents

Abstract

PURPOSE:To miniaturize a whole device and to attain high performance by providing the serial circuit of an inductance and a capacitance in the output terminal of an element in parallel with an output fetching line and setting the value to that which makes serial resonance by means of a frequency twice as much as an action frequency. CONSTITUTION:The inductance L2 and the capacitance C2 are connected in serial. When the values of L2 and C2 satisfy L2.C2=(1/2pif2)<2> (f2 is the frequency which is twice as much as the action frequency), serial oscillation occurs and it becomes short with respect to a second higher harmonic. In the action frequency on the other hand, it comes to a certain impedance, and it comes to that the impedance and the impedance of FET are connected in parallel. With adequately setting the value of L1, L1' and C1 with respect to the total impedance, matching is taken with respect to the action frequency and connection is attained to an output strip line. As a result, a circuit which comes short with respect to the second higher harmonic components in the transistor output terminal that is effective for improving the efficiency of the amplifier can be realized in a considerably small area.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a daytime frequency amplifier circuit, more specifically to an amplifier using semiconductor elements in a high frequency region, and particularly to a circuit configuration suitable for increasing efficiency.

[Conventional technology]

Conventionally, it has been known to provide a circuit that takes into account harmonic impedance on the output side as a means for increasing the efficiency of a high frequency amplifier. For example, Microwave Research Group materials (MW83
-24) states that if the output side impedance is made zero for even harmonics and infinite for odd harmonics, an efficiency close to 100% can be theoretically obtained. Furthermore, an example using a distributed constant line is described as a specific circuit configuration.

[Problem to be solved by the invention]

In the above conventional technology, the output side impedance is constructed using a distributed constant line, such as a strip line or a coaxial line, and therefore becomes large when the frequency is relatively low (for example, at I GHz, one wavelength is 7.5 GHz). 5cm), it is necessary to make sure that the voltage does not become zero at the output end of the element due to bonding lines, etc. to the output end of the element, and it is necessary to configure the circuit at a position relatively far from the element to make it zero at the output end of the element.
Efficiency decreases due to losses during that time.

An object of the present invention is to realize a high-frequency amplifier circuit that is compact and has high efficiency by accurately reducing the impedance to double harmonics to zero at the element output end.

[Means to solve the problem]

The above purpose is to provide a series circuit of inductance and capacitance using lumped constants at the output end of the element in parallel with the output line, ground one end of the series circuit, and set the values of the inductance and capacitance to twice the operating frequency. This is achieved by setting the frequency to a value that causes series resonance. For example, a bonding line from the output end of the element can be used as the inductance due to a lumped constant, a chip capacitor can be used as the capacitance, and the operating frequency I
Considering the case of GHz, 25μmφ length 2ml11
It becomes about 2mH, and t=100. Thickness: 0.5mm.

/ area 1,5 mm2. It becomes about 3 pF, and this series circuit becomes a short circuit at 2 GHz, which is twice the frequency.

That is, the circuit for the above purpose can be realized in an extremely small area with an element frequency of 11 m. On the other hand, if this is configured with a distributed constant circuit, the length of the 2 GHz 1/4 wavelength stub will be approximately 15+ nm on a commonly used alumina substrate, and the condition for shorting at the element output end will be satisfied due to the effect of the bonding line. requires a complex circuit.

[Effect]

The operation of the present invention will be explained with reference to FIG. Reference numeral 1 denotes a field effect transistor (FET), which operates as a source grounded. An inductance L2 and a capacitance c2 are connected in series between the drain terminal, which is the output end of this FET, and the ground. (7) If L x and Cx (D value is L! ・cx = (1/2πfx)", where f2 is twice the operating frequency, series resonance occurs and On the other hand, at the operating frequency, there is a certain impedance, and this impedance and F
The impedance of ET is connected in parallel.

It is not necessary to provide a lumped constant circuit for this total impedance, and a strip line may be used for matching the fundamental wave.

〔Example〕

Hereinafter, it will be explained in detail using examples.

FIG. 2 shows an embodiment of the high frequency amplifier according to the present invention,
Metal lines 4 and 5 are bonded to output bonding pads 2 of transistor chip 1 and connected to capacitors 6 and 7 formed by pads on dielectric chip 8.

The chip capacitor 7 is connected to the output strip line 10 by a metal m9. In the figure, 3 is an input bonding pad, 12 is an input side metal line, and 11 is a dielectric substrate forming a strip line on the output side. In such a structure, the inductance of the metal wire 4 and the capacitance of the capacitor 6 are L2. Corresponding to C2, the length and number of metal wires 4 and the pad area of capacitor 6 are adjusted so that series resonance occurs at a frequency twice the operating frequency.

FIG. 3 is a block diagram of another embodiment of the present invention, in which a dielectric chip 8 is provided between the transistor chip 1 and the output strip line 10, and two rows of pads 6 and 7 forming capacitors are provided on the dielectric chip 8. This is the case when they are arranged so that they are lined up.

The above figures 2 and 3 show one dielectric chip "2 to 2".
Although pads forming two capacitors are provided, it is not necessary to use one dielectric chip, and two dielectric chips may be used.

FIG. 4 shows another embodiment, in which the matching circuit L s + L t 'r Cs for the operating frequency shown in FIG. 1 is not used. That is, one pad 6 forming a capacitor is provided on the dielectric chip 8 provided between the transistor chip 1 and the output strip line 10, and the inductance of the metal wire 4 and the capacitance of the pad 6 are doubled. Set so that series resonance occurs with respect to the frequency.

FIG. 5 shows another embodiment in which a capacitor forming capacitance C2 is provided on a dielectric substrate forming an output strip line.

FIG. 6 is a block diagram of another embodiment of the present invention, in which a transistor and a circuit are formed on the same substrate.
In the MIC type amplifier circuit, the output terminal of the transistor (F
In ET, this is a case where spiral inductance and capacitance are connected in parallel to the output strip line 10 (train electrode), and the spiral line 4A and metal wire 4 are connected in parallel to the output strip line 10.
The sum of the inductances of B and the capacitance of capacitor 6' is set to cause series resonance. Note that 13 is an input line on the gate side, and 14 is a source electrode.

In the figure, the same circuit is provided on both sides of the output stop line, but it is also effective to use only one side.

〔Effect of the invention〕

According to the present invention, a circuit that is short-circuited to the second harmonic component at the transistor output terminal, which is effective for improving the efficiency of an amplifier, can be realized in an extremely small area of several mm2, and as a result, the circuit can be installed within a package. It is possible to create a package that is suitable for increasing the efficiency of transistors.
In turn, the efficiency of the transmitting/receiving device can be improved by using the amplifier, and the overall device can be made smaller and have higher performance.

[Brief explanation of the drawing]

FIG. 1 shows an equivalent circuit of the present invention, and FIGS. 2 to 6 are top views of embodiments of a high-frequency amplifier according to the present invention. ]... 1 ~ transistor chip, 2... bonding pad for output, 3... bonding pad for input, 4
゜5...Metal wire, 6,7...Capacitor, 8...
Dielectric chip, 9... Metal wire, 10... Output strip line, ] 1... Dielectric substrate, 12... Input end metal wire, 13... Input line, 14... Source electrode.

Claims (1)

[Claims] 1. In a high frequency amplifier circuit using a semiconductor element, a series circuit of an inductor and a capacitor is provided at the output end of the semiconductor element in parallel with an output line, and one end of the series circuit is grounded, A high frequency amplifier circuit characterized in that the inductance of the inductor and the capacitance of the capacitor are set to values that cause series resonance at a frequency twice the operating frequency. 2. The high frequency amplifier circuit according to claim 1, wherein the capacitor is a chip capacitor using a dielectric, and the inductor is a metal wire connecting the chip capacitor and a bonding pad of the semiconductor element. . 3. In claim 2, the chip capacitor is provided between the semiconductor element and the output strip line, and each line does not come into contact with both the capacitor and the output line from the bonding pad of the semiconductor element. A high frequency amplifier circuit characterized by being connected as follows. 4. The high frequency amplifier circuit according to claim 2, wherein the chip capacitor is provided on the same substrate as a dielectric substrate constituting the output strip line. 5. In claim 2, a second capacitor is provided on the same dielectric material as the chip capacitor, and the bonding pad of the semiconductor element, the second capacitor, and the output line are connected by lead wires. A high frequency amplification circuit featuring: 6. The high frequency amplifier circuit according to claim 5, wherein a dielectric chip having two types of capacitors is provided between the semiconductor element and the output strip line.