JPS61199306A - Frequency converter - Google Patents

Abstract

PURPOSE:To eliminate the need for an adjusting device for variance in characteristic due to a frequency converter between two receivers of a radio equipment of a diversity reception system by integrating the circuit of two 2-gate FETs so as to uniform the characteristic, connecting the 2nd gate and applying a local oscillation signal wave of the same amplitude. CONSTITUTION:In applying a local oscillation signal from a terminal 16, the signal is fed to the 2nd gate of the two FETs 13 through a matching circuit 11 at the same amplitude. A reception signal frequency is applied from input terminals 15 and 17, resulting that the signal is fed to the 1st gate of the FETs 13 through a matching circuit 12. The local oscillation signal wave and the reception signal wave are mixed at the non-linear part in the operating region of the FETs 13, the addition of the frequency, difference, the local oscillation signal and the reception signal appear at the drain. The matching circuit 14 picks up only the difference frequency between the local oscillation signal and the reception signal and the result is given to output terminals 18, 20. The FETs 13 are integrated FETs, their characteristics are uniform and then the signal transmission characteristics from the input 15 to the output 18 and from the input 17 to the output 20 are uniform.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention mainly relates to a receiving frequency converter in a wireless device.

(Prior Art) In the case of a configuration system in which two receivers are used in a conventional diversity reception radio device, two separate frequency converters are used as reception frequency converters.

These frequency converters have variations in conversion loss and conversion noise figure, and as shown in Figure 2, the balance of reception sensitivity and reception No. 4 detection output between reception circuit-1 and reception circuit-2 is In order to achieve this, each frequency converter is provided with an adjustment mechanism or the characteristics of the frequency converter are selected. In addition, in Fig. 2, 1 is the receiving anti-9, 2 is the receiving filter,
3 is a frequency converter, 4 is a local oscillator signal wave distribution circuit, 5 is a local oscillator, 6 is an intermediate frequency amplification/demodulator, 7 is a baseband switch, 8 is a demodulation output terminal, and 9 is a received signal strength output terminal. be.

(Problems to be Solved by the Invention) However, in the above configuration, an adjustment mechanism is required to maintain balance, and time and adjustment devices are required for adjustment, or for characteristic selection. The product yield rate for frequency converters is poor, and the cost of wireless devices is unavoidably increased.

This invention eliminates the variation in the characteristics of the two frequency converters described above, further reduces the size, eliminates the need for adjustment of the wireless device, and facilitates characteristic selection, and enables low-cost wireless devices and miniaturized wireless devices. The purpose is to provide a wireless device.

(Means for Solving the Problems) A feature of the present invention for achieving the above object is to frequency-convert the received signals from the two received signal input terminals into a single local oscillation signal. A frequency converter having two systems of frequency conversion circuits that provide an intermediate frequency output of A signal is applied, each second gate being connected in common to a frequency converter to which the local oscillation signal is applied.

(Function) In the above configuration, two field effect transistors (FE
T) is integrated and has uniform characteristics.

A received signal is applied to the first gate of each FET, and the second gate of each FET is connected in common and a single local oscillation signal is applied to the second gate of each FET. Therefore, the two systems of frequency conversion circuits using two PETs have uniform frequency conversion loss and uniform conversion noise figure.

(Example) FIG. 1 is a circuit diagram showing an example of the present invention.
5 and 17 are reception frequency input terminals. ]2 is a matching circuit for the receiving frequency, which is located between the first gate of the FET shown in ]3 and the input terminal 15 or 17 for impedance matching. 16 is an input terminal for a local oscillation wave. A matching circuit 11 is tuned to the local oscillation wave and is located between the second gate of the FET 13 and the input terminal 16 for impedance matching.

18.20 is an intermediate frequency output terminal. 14 is an intermediate frequency matching circuit, which is tuned to the intermediate frequency and connects 13 FEs.
It is located between the T drain and the output terminals 18 and 20 and performs impedance matching. 19 is a power supply voltage supply terminal. FE
The second gates of T13 are connected to each other and to the matching circuit 11. The source of FET 13 is grounded in terms of high frequency. When a local oscillation signal is supplied from the terminal 16, the signal is applied to the second gates of the two FETs 13 with the same amplitude through the matching circuit 11. The received No. 4 frequency is supplied from input terminals 15 and 17, and passed through the matching circuit 12 to D F
Receive No. 4 is added to the first gate of ET 13, respectively.

In the non-linear part of the operating region of FET 13, the local oscillation signal wave and the received signal wave are mixed, and the sum of their frequencies, the difference 2
Local oscillator signal waves, received signal waves, etc. appear at the drain.

The matching circuit 14 extracts only the difference frequency between the local oscillation signal wave and the received signal wave and outputs it to output terminals 18 and 20.

Further, the circuit is formed so that the signal input from the input terminal 15 is frequency-converted to the output terminal 20, and the signal input from the input terminal 17 is frequency-converted to the output terminal 18, so that the amount of leakage is extremely small.

In the above operation, F'ET 13 is an integrated F
ET, the characteristics are uniform, local oscillation signal waves of the same amplitude are applied to the second gates, and matching circuits 12 and 14 use the same circuits, so in this frequency converter, the input 15 is connected to the output 18. The signal transfer characteristics from the input 17 to the output 20 are uniform.

(Effects of the Invention) As explained above, according to the present invention, the 2-gate FET
After integrating two FETs to make the characteristics uniform, the second gate was connected to add a local oscillation signal wave of the same amplitude, so the frequency conversion characteristics of the two FETs K became uniform, creating a diversity receiving system. It is possible to eliminate the characteristic variation adjustment mechanism by the frequency converter between the two receivers of the wireless device, and the number of matching circuits for the second gate of the FET can be reduced by one, making the frequency converter smaller than the conventional one. We can expect that.

[Brief explanation of the drawing]

FIG. 1 is a block diagram of a frequency converter according to the present invention, FIG.
The figure is a block diagram of a receiver of a conventional diversity reception radio device. 1 is a reception antenna, 2 is a reception filter, 3 is a frequency converter, 4 is a local oscillation signal wave distributor, 5 is a local oscillator, 6
is an intermediate frequency amplifier/demodulator, 7 is a baseband switch,
8 is a demodulation output terminal, 11 is a local oscillation signal wave matching circuit, 1
2 is a receiving signal matching circuit, 13 is a 2-gate FET, 1
4 is an intermediate frequency signal wave matching circuit, 15.17 is a received signal wave input terminal, 16 is a local oscillation signal wave input terminal, 18.2
0 is an intermediate frequency signal output terminal, and 19 is a power supply voltage supply terminal.

Claims (1)

[Claims] In a frequency converter having two systems of frequency conversion circuits that frequency convert received signals from two received signal input terminals using a single local oscillation signal and provide two intermediate frequency outputs, two integrated A two-gate field effect transistor is provided, a first gate of each is applied with a reception signal from a reception signal input terminal, and a second gate of each is connected in common and the local oscillation signal is applied. A frequency converter featuring: