KR20140021285A - Wideband frequency converting apparatus - Google Patents

Abstract

The present invention relates to a broadband frequency conversion device which includes: a first frequency mixer for down-converting a received frequency according to a first local oscillation frequency generated in a first local oscillator to a first intermediate frequency; a second frequency mixer for down-converting the first intermediate frequency according to a second local oscillation frequency generated in a second local oscillator to a second intermediate frequency; and a control unit for controlling the first local oscillator to make the first intermediate frequency correspond to an image frequency which is generated by the second local oscillation frequency and second intermediate frequency according to the received frequency. According to the present invention, a receivable frequency range can be extended while maintaining a sweep range of the first local oscillation frequency, and the spurious performance can be improved. [Reference numerals] (170) Control unit

Description

[0001] WIDEBAND FREQUENCY CONVERTING APPARATUS [0002]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates generally to a wideband frequency converter and, more particularly, to a wideband frequency converter for extending a reception frequency range and improving spurious performance while maintaining a sweep range of a first local oscillation frequency. Conversion device.

In recent wireless communication technology, a transmitter transmits an RF signal up-converted to a high frequency for transmission over a long distance, and a receiver down-converts the RF signal to a low frequency to perform analog signal processing or digital signal processing, To a baseband frequency.

In general, the frequency conversion method is divided into a homodyne method and a heterodyne method.

The homodyne method is referred to as a direct conversion method and converts an RF signal directly to a baseband frequency. On the other hand, the heterodyne method converts the RF signal into a low frequency band stepwise.

A receiver with a homodyne structure can be considered as the most ideal frequency converter. However, in the homodyne structure, because the center frequency of the RF signal to be received is the same as the local oscillation frequency of the local oscillator, it is impossible to perform filtering and self-mixing is caused due to the operation of the frequency mixer There is a problem.

In addition, it is technically very difficult to convert a wideband signal of several hundred octaves or more to a low frequency at a time.

Therefore, a super-heterodyne conversion structure in which frequency conversion is performed through two or more frequency mixing processes is applied to most receivers.

Such a superheterodyne conversion structure has advantages in terms of filter implementation.

Generally, the Q-factor of the filter for determining the reception performance is determined by the resonance frequency (? ₀ ) and the bandwidth (BW) as shown in the following equation (1).

That is, the higher the selectivity, the greater the signal loss, and at lower frequencies, the higher selectivity filter can be implemented with less loss.

A serious problem occurring in a receiver of such a superheterodyne conversion structure is that the image frequency and harmonic frequency generated due to the nonlinear conversion characteristic of the frequency mixer and the spurious generated due to the frequency mixing of the local oscillation frequency ) Signal.

The image frequency means a frequency spectrum capable of generating a spurious signal at an intermediate frequency generated by a frequency mixer. The image frequency is defined by the following equation (2) according to the logarithmic arrangement of the mixing frequency.

Here, f _RF represents the reception frequency and f _IF represents the intermediate frequency.

Therefore, when designing a superheterodyne receiver, the receiver should be designed to have enough frequency spacing to sufficiently attenuate the intermediate frequency and the image frequency before converting the reception frequency to the intermediate frequency through the frequency mixer.

In the case of the narrowband receiver, since it has a sufficient degree of design freedom, it is possible to apply various schemes in consideration of the above-mentioned problems.

However, in the case of a wideband receiver used in a radio wave measuring apparatus or a radio wave monitoring receiving apparatus, it is very difficult to design a system that satisfies the wideband reception performance without deteriorating the phase noise characteristic and the spurious performance in the V / UHF band.

In order to easily implement the V / UHF band broadband receiver, it is possible to consider a method in which the intermediate frequency is designed to be higher than the reception frequency so that the RF signal to be received and the image frequency are sufficiently separated to be filtered.

Likewise, a method of designing the local oscillation frequency at a frequency significantly lower than the reception frequency or designing the frequency at a very high frequency may be considered to separate the local oscillation frequency from the reception frequency.

However, it is almost impossible to implement a frequency conversion device capable of receiving signals in the UHF and SHF bands using a local oscillation frequency lower than the VHF band in a V / UHF band wideband receiver.

Therefore, a frequency synthesizer using a high local oscillation frequency can be constructed, and the local oscillation frequency can be varied by being offset by the offset of the reception frequency, thereby realizing a wideband frequency conversion device.

However, it is practically impossible and inefficient to sweep the local oscillation frequency infinitely high in order to expand the reception frequency of the broadband receiver.

A frequency synthesizer such as an oscillator (YIG oscillator) can be used for implementing a wideband receiver in the V / UHF band. However, the circuit configuration is complicated and has limitations in realizing high frequency synthesis resolution.

Related Prior Art Korean Patent Publication No. 2010-0129542 (published on Dec. 12, 2010, entitled: Multiple Frequency Band Receiver) is available.

SUMMARY OF THE INVENTION The present invention has been made in order to overcome the above-mentioned problems, and it is an object of the present invention to provide a wideband frequency conversion apparatus and method which can improve a spurious performance by extending a reception frequency range while maintaining a sweep range of a first local oscillation frequency, The purpose of the device is to provide.

According to an aspect of the present invention, there is provided a wideband frequency converter comprising: a first frequency mixer for downconverting a reception frequency to a first intermediate frequency according to a first local oscillation frequency generated in a first local oscillator; A second frequency mixer for down-converting the first intermediate frequency to a second intermediate frequency according to a second local oscillation frequency generated by the second local oscillator; And a controller for controlling the first local oscillator so that the first intermediate frequency corresponds to an image frequency generated by the second local oscillation frequency and the second intermediate frequency according to the reception frequency.

In the present invention, if the reception frequency is higher than a preset frequency, the first intermediate frequency is selected as a lower frequency of the image frequency.

The present invention further includes a switch for selecting a band-pass filter between the first frequency mixer and the second frequency mixer according to the first intermediate frequency.

The present invention further includes a filter bank located at a front end of the first frequency mixer and selectively passing the reception frequency according to the first local oscillation frequency.

According to another aspect of the present invention, there is provided a wideband frequency converter comprising: a first frequency mixer for down-converting a reception frequency to a first intermediate frequency according to a first local oscillation frequency generated in a first local oscillator; A second frequency mixer for converting the first intermediate frequency to a second intermediate frequency according to a second local oscillation frequency generated by the second local oscillator; An auxiliary frequency mixer positioned upstream of the first frequency mixer to down-convert the reception frequency according to an auxiliary frequency divided from the second local oscillation frequency and provide the down-converted to the first frequency mixer; A switch for inputting the reception frequency to the auxiliary frequency mixer; And a controller for controlling the switch such that the reception frequency is selectively inputted to the auxiliary frequency mixer, and for controlling the auxiliary frequency by controlling the frequency divider.

In the present invention, if the reception frequency is equal to or higher than a preset frequency, the reception frequency is input to the auxiliary frequency mixer.

The auxiliary frequency is set to the second local oscillation frequency when the reception frequency is greater than the sum of the auxiliary frequency and the set frequency.

In the present invention, the auxiliary frequency is divided into sub-harmonics of the second local oscillation frequency.

The controller may control the first local oscillator so that the first intermediate frequency corresponds to an image frequency generated by the second local oscillation frequency and the second intermediate frequency.

According to the present invention, since the range of the reception frequency can be extended nearly twice while maintaining the sweep range of the first local oscillation frequency as it is, low phase noise characteristics and excellent level flatness characteristics can be realized.

Further, according to the present invention, since the first intermediate frequency corresponds to the image frequency by the second intermediate oscillation frequency and the second local oscillation frequency, generation of spurious signals due to use of different frequencies can be suppressed, thereby improving spurious performance can do.

Further, according to the present invention, by providing an additional frequency down conversion path using subharmonics in which the second local oscillation frequency is divided by 1 / N (N = 1, 2, 3) The generation of spurious signals can be suppressed, and the spurious performance can be improved.

1 is a diagram illustrating a structure of a wide-band frequency converter according to an embodiment of the present invention.
2 is a diagram illustrating a frequency relationship applied to a wideband frequency converter according to an embodiment of the present invention.
3 is a diagram illustrating a frequency conversion process of a wideband frequency converter according to an exemplary embodiment of the present invention in a table format.
4 is a diagram illustrating a structure of a wideband frequency converter according to another embodiment of the present invention.
FIG. 5 is a diagram illustrating a frequency conversion process of a wideband frequency converter according to another embodiment of the present invention in a table format. Referring to FIG.

Hereinafter, a wideband frequency converter according to the present invention will be described in detail with reference to the accompanying drawings. In this process, the thicknesses of the lines and the sizes of the components shown in the drawings may be exaggerated for clarity and convenience of explanation. In addition, terms to be described below are terms defined in consideration of functions in the present invention, which may vary according to the intention or convention of a user or an operator. Therefore, definitions of these terms should be made based on the contents throughout the specification.

FIG. 1 is a diagram illustrating a structure of a wideband frequency converter according to an embodiment of the present invention. FIG. 2 is a diagram illustrating a frequency relationship applied to a wideband frequency converter according to an embodiment of the present invention. Is a diagram illustrating a frequency conversion process of the wideband frequency converter according to an exemplary embodiment of the present invention in the form of a table.

1, a wideband frequency converter according to an exemplary embodiment of the present invention includes a band selection filter 100, a first frequency mixer 110, a first local oscillator 120, a second frequency mixer 130 A second local oscillator 140, a switch 150, a band-pass filter 160, and a controller 170.

To have a broadband frequency converter according to the present invention based on the set frequency _{(f RF (k))} low-frequency _{(f RF (1) ~ f} RF (k)) and the high frequency band _{(f RF (k) ~ f} RF (N ₎ Can be input and the low frequency bands _{fRF (1)} to fRF _(k ) or the high frequency bands _{fRF (k)} to fRF _(N) selected by the band selection filter 100 can be input _. Are input to the first frequency mixer 110. [

The band selection filter 100 removes the image frequency of the first frequency mixer 110 and _outputs the low frequency bands f _{RF (1)} to f _{RF (k)} according to the first local oscillation frequency f _LO1 , Or a filter bank that is controlled to selectively pass the high frequency bands f _{RF (k)} to f _{RF (N)} .

The band pass filter 160 removes the image frequency in the frequency conversion process and generates a first local oscillation frequency f _LO1 , a second local oscillation frequency f _LO2 , a first high intermediate frequency f _{IF1_H} , And _{filters the} intermediate frequency f _{IF1_L} and the second intermediate frequency f _IF2 , respectively.

The first local oscillator 120 generates a first local oscillation frequency f _LO1 and provides it to the first frequency mixer 110.

The first frequency mixer 110 mixes the reception frequency f _RF of the RF signal inputted through the band selection filter 100 with the first local oscillation frequency f _LO1 input from the first local oscillator 120 And downconverts to the first intermediate frequency f _IF1 . This can be expressed by the following equation (3).

At this time, the first local oscillation frequency f _LO1 is a frequency at which the reception frequency f _RF is one of the first high intermediate frequency f _{IF1_H} or the first low intermediate frequency f _{IF1_L} through the first frequency mixer 110 May be swept to be downconverted. The first high intermediate frequency f _{IF1_H} and the first low intermediate frequency f _{IF1_L are} determined by the second local oscillation frequency f _LO2 and the image frequency generated by the second intermediate frequency f _IF2 , A detailed description will be given later.

The first high intermediate frequency with a first frequency mixer (110), (f _{IF1_H)} or converted to a first low intermediate frequency (f _{IF1_L)} signal is sent to the band-pass filter 160 by the operation of the switch 150 The path is selected.

The second local oscillator 140 generates the second local oscillation frequency f _LO2 and provides it to the second frequency mixer 130.

The second frequency mixer 130 receives the first high intermediate frequency f _{IF1_H} generated by the first frequency mixer 110 or the first low intermediate frequency f _{IF1_L} from the second local oscillator 140 And downconverts to the second intermediate frequency f _IF2 according to the two local oscillation frequency f _LO2 .

The controller 170 is a first high intermediate frequency (f _{IF1 _H)} and the first low intermediate frequency (f _{IF1 _L),} the second local oscillation frequency (f _LO2) and the second intermediate-frequency images generated by the (f _IF2), And controls the first local oscillator 120 and the second local oscillator 140 to correspond to the frequency.

Specifically, the controller 170 first determines the second intermediate frequency f _IF2 and the second local oscillation frequency f _LO2 , and thereby determines the first intermediate frequency f _{IF1_H} and the first low intermediate frequency f _{IF1_L} ).

At this time, the controller 170 sets the high frequency of the image frequency generated by the second intermediate frequency f _IF2 and the second local oscillation frequency f _LO2 to the first high intermediate frequency f _{IF1_H} , 1 low intermediate frequency ( _{fIF1_L} ).

2, the first high intermediate frequency f _{IF1_H} and the first low intermediate frequency f _{IF1_L} are set to a second intermediate frequency f _IF2 based on the second local oscillation frequency f _LO2 , Of the image frequency. This can be expressed by the following equation (4).

As described above, when the first intermediate frequency corresponds to the image frequency by the second intermediate frequency f _IF2 and the second local oscillation frequency f _LO2 , generation of a spurious signal by use of the heterogeneous frequency is suppressed So that the spurious performance can be improved.

Thereafter, the controller 170 compares the reception frequency f _RF with the set frequency f _{RF (k)} so as to perform down conversion on the first high intermediate frequency f _{IF1_H} or the first low intermediate frequency f _{IF1_L} . 1 local oscillation frequency f _LO1 , and controls the switch 150 to select the band-pass filter 160.

The control unit 170 determines whether the reception frequency f _RF is higher than the first high intermediate frequency f _{IF1_H} through the first frequency mixer 110 when the reception frequency f _RF is equal to or lower than the set frequency f _{RF (k)} ) adjusting the first local oscillator frequency (f _LO1) to be down-converted to, and controls the switch 150 to select the band pass filter 160 to a first high intermediate frequency (f _{IF1_H).}

On the other hand, the control section 170 is the reception frequency (f _RF) is set the frequency (f _{RF (k))} or more, the reception frequency (f _RF) is the first low intermediate frequency through a first frequency mixer (110), (f _{IF1_L} ) adjusting the first local oscillator frequency (f _LO1) to be down-converted to, and controls the switch 150 to select the band pass filter 160 to the first low intermediate frequency (f _{IF1_L).}

The first local oscillation frequency f _LO1 for down-converting the reception frequency f _RF to the first high intermediate frequency f _{IF1_H} or the first low intermediate frequency f _{IF1_L} can be expressed by the following equation same.

An example of such a series of frequency conversion processes will be described with reference to FIG.

3, the set frequency _{(f RF (k))} is 3000 [MHz], and the low frequency band of the RF signal _{(f RF (1) ~ f} RF (k)) is from 30 [MHz] 3000 [ MHz] range of the V / UHF band.

If the second intermediate frequency f _IF2 is determined to be 1050 [MHz] and the second local oscillation frequency f _LO2 is determined to be 3150 [MHz], the first high intermediate frequency f _{IF1_H} may be _calculated according to the _above- And the first low intermediate frequency f _{IF1_L are} determined to be 4200 [MHz] (3150 + 1050) and 2100 [MHz] (3150-1050), respectively.

If the reception frequency f _RF falls within the range of 30 [MHz] to 3000 [MHz], the controller 170 sets the reception frequency f _RF to the first high intermediate frequency f _{IF1_H)} to thereby sweep (sweep) within a range of the first local oscillator frequency (f _LO1) to 4230 [MHz] (4200 + 30 ) from 7200 [MHz] (4200 + 3000 ) to be down-converted.

On the other hand, when the reception frequency f _RF is equal to or greater than 3000 [MHz], the controller 170 sets the reception frequency f _RF to the first low intermediate frequency f _{IF1_L} according to the _above- Sweeps the local oscillation frequency (f _LO1 ) to 5100 [MHz] (3000 + 2100) or more.

If the sweep range of the first local oscillation frequency f _LO1 is maintained at the same level as that described above, the first local oscillation frequency f _LO1 is changed from 5100 [MHz] to 7200 [MHz] Range, the range of the receiving frequency f _RF is 3000 [MHz] to 5100 [MHz] (7200-2100).

That is, the range of the reception frequency f _RF is changed from 30 [MHz] to 3000 [MHz] to 30 [MHz] to 5100 [MHz] while maintaining the sweep range of the first local oscillation frequency f _LO1 . To about two times.

As described above, according to the wide-band frequency converter of the present invention, since the range of the reception frequency can be extended almost twice without an additional wide-band frequency synthesizer or a frequency multiplier, low phase noise characteristics and excellent level flatness characteristics can be realized have.

FIG. 4 is a diagram illustrating a structure of a wide-band frequency converter according to another embodiment of the present invention. FIG. 5 is an exemplary diagram illustrating a frequency conversion process of a wide-band frequency converter according to another embodiment of the present invention in the form of a table to be.

In the above-described embodiment, the image frequency generated by the second local oscillation frequency f _LO2 and the second intermediate frequency f _IF2 is the first high intermediate frequency f _{IF1_H} or the first intermediate frequency f _IF2 depending on the reception frequency f _RF . And the first local oscillation frequency f _LO1 is adjusted to be the low intermediate frequency f _{IF1_L} to extend the reception frequency f _RF range.

However, alternatively the reception frequency (f _RF) to a different frequency down-conversion path in accordance with a first local oscillation frequency sweep range (f _LO1) receive frequency, while maintaining the (sweep range) (f _RF) may be scaled to range have.

4, a wideband frequency converter according to another embodiment of the present invention includes an auxiliary frequency mixer 210, a switch 220, a first frequency mixer 230, a first local oscillator 240, 2 frequency mixer 250, a second local oscillator 260, a frequency divider 270, a bandpass filter 280, and a controller 290.

Secondary frequency mixer 210 and the switch 220 is a second local oscillator frequency for the first located at the front end sets the frequency of the frequency mixer (230), (f _{RF (k))} over a reception frequency (f _RF) (f _LO2 ) ≪ / RTI > of the sub-harmonic characteristic of the input signal.

That is, if the reception frequency f _RF is greater than or equal to the set frequency f _{RF (k)} , down conversion through the auxiliary frequency mixer 210 is performed before the down-conversion through the first frequency mixer 230 is performed.

At this time, the auxiliary frequency mixer 210 is _divided into 1 / N (N = 1, 2, 3) subharmonic components of the second local oscillation frequency f _LO2 generated by the second local oscillator 260 The receiving frequency f _RF can be down-converted according to the provided auxiliary frequency f _LO2 / N.

In this manner, when the down-conversion is performed in accordance with the auxiliary frequency f _LO2 / N having the sub-harmonic characteristic, the generation of spurious signals due to the use of the heterogeneous frequency can be suppressed, thereby improving the spurious performance .

Furthermore, since the receiving frequency f _{RF which} is equal to or higher than the set frequency f _{RF (k)} is down-converted in advance by a predetermined level, the sweep range of the first local oscillation frequency f _LO1 is maintained, it is possible to extend the range of the (f _RF).

The first frequency mixer 230 is configured to mix the received frequencies f _{RF (1)} to f _{RF (k)} below the set frequency f _{RF (k)} Converted to the first intermediate frequency f _IF1 according to the first local oscillation frequency f _LO1 input from the local oscillator 240. [

At this time, the first intermediate frequency f _IF1 may be determined to be one of the second local oscillation frequency f _LO2 and the image frequency generated by the second intermediate frequency f _IF2 .

The second local oscillator 260 generates the second local oscillation frequency f _{LO2 and} provides the second local oscillation frequency f _LO2 to the second frequency mixer 250.

The second frequency mixer 250 downconverts the first intermediate frequency f _IF1 to the second intermediate frequency f _IF2 in accordance with the second local oscillation frequency f _LO2 input from the second local oscillator 260 .

The second local oscillation frequency f _LO2 generated by the second local oscillator 260 is supplied to the auxiliary frequency mixer 210 through the frequency divider 270. At this time, the frequency divider 270 may divide the second local oscillation frequency f _LO2 by 1 / N (N = 1, 2, 3) and provide the divided frequency to the auxiliary frequency mixer 210.

Control unit 290 is the reception frequency (f _RF) in accordance with the reception frequency by controlling the switch (220), (f _RF), a second frequency-selective and input to a mixer 210, a frequency divider secondary frequency mixer by controlling (270) (F _LO2 / N) provided to the frequency _converter 210.

Specifically, the receiving frequency (f _RF) is set the frequency (f _{RF (k))} or less, the control section 290 directly to the reception frequency (f _RF) of a first frequency mixer 230 by controlling the switch 220 So that two down conversion is performed.

On the other hand, when the reception frequency f _RF is equal to or higher than the set frequency f _{RF (k)} , the control unit 290 controls the switch 220 to input the reception frequency f _RF to the auxiliary frequency mixer 210, So that the conference down conversion is performed.

At this time, when the reception frequency f _RF is larger than the sum of the auxiliary frequency f _LO2 / N and the set frequency f _{RF (k)} , the controller 290 sets N to 1, 210 to perform down conversion according to the second local oscillation frequency f _LO2 .

The controller 290 controls the first local oscillator frequency f _IF1 so that the first intermediate frequency f _IF1 corresponds to either the second local oscillation frequency f _LO2 or the image frequency generated by the second intermediate frequency f _IF2 , (240).

An example of such a series of frequency conversion processes will be described with reference to FIG.

5, the set frequency f _{RF (k)} is 3000 MHz and the low frequency bands f _{RF (1)} to f _{RF (k)} of the RF signal are changed from 30 [MHz] MHz] range of the V / UHF band.

In this case, if the second intermediate frequency f _IF2 is 1050 [MHz] and the second local oscillation frequency f _LO2 is 3150 [MHz], then the first intermediate frequency f _IF1 is 4200 [MHz] (3150 + 1050).

If the reception frequency f _RF falls within the range of 30 [MHz] to 3000 [MHz], the controller 290 controls the switch 220 to transmit the reception frequency f _RF to the first frequency mixer 230, .

The controller 290 sets the first local oscillation frequency f _LO1 to 4230 [MHz] (4200 + 30) so that the reception frequency f _RF is down-converted to the first intermediate frequency f _IF1 according to Equation (5) To 7200 [MHz] (4200 + 3000).

On the other hand, when the reception frequency f _RF is equal to or more than 3000 [MHz] and the auxiliary frequency f _LO2 / 3 is equal to or less than the sum of the set frequency f _{RF (k)} , the control unit 290 controls the switch 220 control input and the reception frequency (f _RF) to the secondary frequency mixer 210, the reception frequency (f _RF), the second local oscillation frequency (f _LO2) 1/3 the auxiliary frequency (f _LO2 / 3) divided by the 1050 [MHz].

That is, when the reception frequency f _RF is 3000 [MHz] to 4050 [MHz], the reception frequency f _RF `passing through the auxiliary frequency mixer 210 is 3000 [ MHz] (4050-1050) and input to the first frequency mixer 230.

On the other hand, when the reception frequency f _RF is larger than the sum of the auxiliary frequency f _LO2 / 3 and the set frequency f _{RF (k)} , the controller 290 sets N in the frequency divider 270 to 1 _Thereby down-converting the reception frequency f _RF in accordance with the second local oscillation frequency f _LO2 .

That is, if the reception frequency f _RF is larger than 4050 [MHz] (1050 + 3000), the down-conversion is performed according to the second local oscillation frequency f _LO2 3150 [MHz] The received reception frequency f _{RF '} is down-converted to 900 [MHz] (4050 - 3150) or more and input to the first frequency mixer 230.

If the sweep range of the first local oscillation frequency f _LO1 is kept at the same level as the above case, the first local oscillation frequency f _LO1 is changed from 5100 [MHz] (900 + 4200) The range of the reception frequency f _RF `passing through the auxiliary frequency mixer 210 ranges from 900 [MHz] to 3000 [MHz] (6150 - 3150) , And the reception frequency (f _RF ) ranges from 4050 [MHz] to 6150 [MHz] (3000 + 3150).

That is, the range of the reception frequency f _RF is changed from 30 [MHz] to 3000 [MHz] to 30 [MHz] to 6150 [MHz] while maintaining the sweep range of the first local oscillation frequency f _LO1 . Can be expanded more than two times.

As described above, according to the wide-band frequency converter of the present invention, the range of the reception frequency can be extended while maintaining the sweep range of the first local oscillation frequency, thereby realizing the low phase noise characteristic and the excellent level flatness characteristic .

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it will be understood by those of ordinary skill in the art that various changes in form and details may be made therein without departing from the spirit and scope of the invention as defined by the appended claims. I will understand. Accordingly, the technical scope of the present invention should be defined by the following claims.

100: band selection filter 110: first frequency mixer
120: first local oscillator 130: second frequency mixer
140: second local oscillator 150: switch
160: band-pass filter 170:
210: auxiliary frequency mixer 220: switch
230: first frequency mixer 240: first local oscillator
250: second frequency mixer 260: second local oscillator
270: Frequency divider 280: Bandpass filter
290: control unit

Claims (9)

A first frequency mixer for down-converting the reception frequency to a first intermediate frequency according to a first local oscillation frequency generated in the first local oscillator;
A second frequency mixer for down-converting the first intermediate frequency to a second intermediate frequency according to a second local oscillation frequency generated by the second local oscillator; And
And a controller for controlling the first local oscillator so that the first intermediate frequency corresponds to an image frequency generated by the second local oscillation frequency and the second intermediate frequency according to the reception frequency.
The wideband frequency converter of claim 1, wherein the first intermediate frequency is selected as a lower frequency among the image frequencies when the reception frequency is greater than or equal to a set frequency.
2. The wideband frequency converter of claim 1, further comprising a switch located between the first frequency mixer and the second frequency mixer to select a bandpass filter according to the first intermediate frequency.
The wideband frequency converter of claim 1, further comprising a filter bank located at a front end of the first frequency mixer and selectively passing the reception frequency according to the first local oscillation frequency.
A first frequency mixer for down-converting the reception frequency to a first intermediate frequency according to a first local oscillation frequency generated in the first local oscillator;
A second frequency mixer for converting the first intermediate frequency to a second intermediate frequency according to a second local oscillation frequency generated by the second local oscillator;
An auxiliary frequency mixer positioned upstream of the first frequency mixer to down-convert the reception frequency according to an auxiliary frequency divided from the second local oscillation frequency and provide the down-converted to the first frequency mixer;
A switch for inputting the reception frequency to the auxiliary frequency mixer; And
And a control unit controlling the switch to selectively input the reception frequency to the auxiliary frequency mixer, and controlling the divider to adjust the auxiliary frequency.
6. The wideband frequency converter of claim 5, wherein the reception frequency is input to the auxiliary frequency mixer when the reception frequency is equal to or higher than a preset frequency.
The method according to claim 6,
Wherein the auxiliary frequency is set to the second local oscillation frequency when the reception frequency is larger than the sum of the auxiliary frequency and the set frequency.
6. The wideband frequency converter of claim 5, wherein the auxiliary frequency is divided into sub-harmonics of the second local oscillation frequency.
6. The wideband frequency of claim 5, wherein the controller controls the first local oscillator such that the first intermediate frequency corresponds to an image frequency generated by the second local oscillation frequency and the second intermediate frequency. Inverter.

Images