KR200222047Y1 - An up/down converter - Google Patents

Abstract

The present invention relates to a transmit / receive frequency up / down converter of a code division multiple access (CDMA) mobile communication system, and more particularly, to a transmit / receive frequency up / down converter having only one PLL synthesizer. It is about.

Conventional transmit / receive frequency up / down converters require two PLL synthesizers, one for the transmit frequency and one for the receive frequency, which has a problem in that the circuit is complicated and the reliability of the product is deteriorated.

The present invention has been made to solve the above problems, the transmission / reception frequency up / down conversion apparatus according to the present invention is a low noise amplification of the RF (RF) signal input to each of the transmission frequency and the reception frequency with a predetermined amplification gain A first downconverter and a second downconverter for converting signals output from the first amplifier and the fifth amplifier into an intermediate frequency; A second amplifier and a sixth amplifier; a first surface elastic filter and a second surface elastic filter for removing adjacent frequencies and harmonics components of the amplified signal; and appropriately adjusting power levels of signals output from the filter. A first variable attenuator and a second variable attenuator; and a third amplifier and a seventh amplifier to compensate for the filter loss generated in the filter; And a first upconverter and a second upconverter for restoring the downconverted signal to a signal having an original frequency, and a first bandpass filter and a second bandpass filter for removing harmonic signals generated during the upconversion. A fourth amplifier and an eighth amplifier for amplifying and finally outputting the band-filtered signal, and a PEL synthesizer providing a local signal mixed during the up / down conversion; And a splitter for uniformly distributing the local signal output from the PEL synthesizer to each of the up converter and the down converter.

As described above, the apparatus for transmitting / receiving frequency up / down according to the present invention has an effect that the reliability of the device is improved due to the simplified circuit, and the number of components forming the peripheral circuit is reduced, thereby reducing the product cost.

Description

Transceiver frequency up / down converter {An up / down converter}

The present invention relates to a transmit / receive frequency up / down converter of a code division multiple access (CDMA) mobile communication system, and more particularly, to a transmit / receive frequency up / down converter using only one PLL synthesizer. It is about.

The transmission / reception frequency up / down converter includes a transmission frequency up / down converter and a reception frequency up / down converter. 1A and 1B are block diagrams illustrating a configuration of a transmission frequency up / down converter and a reception frequency up / down converter of a transmission / reception frequency up / down converter according to the prior art, respectively.

As shown, the up / down converter for transmitting frequency (hereinafter referred to as transmit converter) and the up / down converter for receiving frequency (hereinafter referred to as receiving converter) are the same in terms of configuration, and only the frequency of the input signal and the PEL synthesizer ( Since only the frequency of the local signal output from 110 is different, a detailed description of the transmission converter and a detailed description of the reception converter will be omitted.

The input RF signal is low noise amplified by the first amplifier 101 with a predetermined amplification gain. The amplified signal is mixed with a local signal output from the PLL synthesizer 110 in the frequency down converter 102 and converted into an intermediate frequency. The conversion loss associated with the down conversion is compensated by the second amplifier 103, and the signal output from the second amplifier 103 is an adjacent frequency generated by the amplifiers 101 and 103 and the down converter 102. And surface elastic filter 104 to remove harmonics components. The signal passed through the filter 104 is input to the variable attenuator 105 to maintain an appropriate signal power level. The signal passing through the variable attenuator 105 is input to the third amplifier 106 to compensate for the filter loss generated when passing through the surface elastic filter 104. The amplified compensated signal is input to a frequency upconverter 107 which restores the downconverted signal by the frequency downconverter 102 to a signal of the original frequency. At this time, the signal input to the frequency up-converter 107 is mixed with the local frequency signal output from the PLL synthesizer 110. This up-converted signal passes through a band pass filter 108 to remove harmonic components generated by the frequency up-converter 107. The fourth amplifier 109 amplifies and outputs the filtered signal to a predetermined signal power level.

However, the conventional transmit / receive frequency up / down converter as described above includes a PL synthesizer 110 separately configured in each of the transmission converter and the reception converter, thereby increasing the production cost thereof, and configuring the PL synthesizer. Since there is one more peripheral circuit to do this, the circuit is complicated and the reliability of the product is low. Had a point.

The present invention has been made to solve the above problems, by using only one PLL synthesizer (PLL synthesizer) to provide the same local signal to the transmission converter and the reception converter, reducing the production cost and product It is a technical object of the present invention to provide a transmission / reception frequency up / down conversion device having improved reliability.

Figure 1a is a block diagram showing the configuration of the up / down converter for the transmission frequency according to the prior art.

Figure 1b is a block diagram showing the configuration of the up / down converter for the receiving frequency according to the prior art.

Figure 2 is a block diagram showing the configuration of the transmission and reception frequency up / down converter according to the present invention.

※ Explanation of codes for main parts of drawing

101, 201. First amplifier 102. Frequency down converter

103, 203. Second amplifier 104. Surface elastic filter

105. Variable Attenuator 106, 206. Third Amplifier

107. Frequency upconverter 108. Bandpass filter

109, 209. Fourth amplifier 110, 219. PLL Synthesizer

202. First downconverter 204. First surface elastic filter

205. First Variable Attenuator 207. First Upconverter

208. First Band Pass Filter 210. Fifth Amplifier

211. Second downconverter 212. Sixth amplifier

213. Second Surface Elastic Filter 214. Second Variable Attenuator

215. Seventh amplifier 216. Second upconverter

217. Second Band Pass Filter 218. Eighth Amplifier

220. Splitter 221. Transceiver frequency up / down inverter

A transmission / reception frequency up / down converter according to the present invention includes a first amplifier for low noise amplifying an RF signal input at a transmission frequency with a predetermined amplification gain; and a signal output from the first amplifier at an intermediate frequency. A first downconverter for converting; and a second amplifier for compensating for the conversion loss generated during the downconversion; and a first surface elastic filter for removing adjacent frequencies and harmonics from signals output from the second amplifier; A first variable attenuator for appropriately adjusting the power level of the signal output from the first surface elastic filter; and a third connected to the output terminal of the first variable attenuator to compensate for the filter loss generated in the first surface elastic filter. A first upconverter for restoring a signal downconverted by the first downconverter to an original frequency signal; A first band pass filter for removing harmonic signals generated during up-conversion; a fourth amplifier for amplifying and finally outputting the band-filtered signal; and an RF signal input at a reception frequency with a predetermined amplification gain. A fifth amplifier for low noise amplification; and a second down converter for converting the signal output from the fifth amplifier to an intermediate frequency; and a sixth amplifier for compensating conversion loss generated during the down conversion by the second down converter; A second surface elastic filter for removing adjacent frequencies and harmonics from the signal output from the sixth amplifier; and a second variable attenuator for appropriately adjusting the power level of the signal output from the second surface elastic filter; and Connected to the output of the second variable attenuator to compensate for the filter losses generated in the second surface elastic filter. A seventh amplifier; and a second upconverter for restoring a signal downconverted by the second downconverter to a signal of an original frequency; and a second band for removing harmonic signals generated during upconversion by the second upconverter. An eighth amplifier for amplifying and finally outputting the bandpass filtered signal; And a splitter for uniformly distributing the local signal output from the PEL synthesizer to each of the up converter and the down converter.

Hereinafter, an embodiment of a transmission / reception frequency up / down converter according to the present invention will be described in detail with reference to the accompanying drawings. In the following description, the same or corresponding members will be denoted by the same reference numerals and detailed description thereof will be omitted.

The first amplifier 201 receives an input RF signal having the same transmission frequency as that of the transmission channel from the base station to the corresponding terminal, and outputs a low noise amplification with a predetermined amplification gain. On the contrary, the fifth amplifier 210 receives a signal having the same reception frequency as that of the reception channel from the terminal to the base station and outputs the low noise amplification with a predetermined amplification gain.

The first down converter 202 receives the amplified signal from the first amplifier 201, mixes it with the local signal from the PLL synthesizer 219, and down-converts the intermediate frequency signal to output it. In this case, the frequency of the intermediate frequency is determined by the frequency of the amplified signal input at the time of mixing and the frequency of the local signal. For example, if the transmission frequency is 1855 MHz and the local signal frequency is 1925 MHz, the intermediate frequency is 70 MHz (1925-1855 [MHz]). The second down converter 211 performs the same function and only the frequency of the input signal is different. If the reception frequency is 1765 MHz and the local signal frequency is 1925 MHz, the intermediate frequency is 160 MHz (1925-1765 [MHz]).

The conversion loss caused by the first down converter 202 is compensated by a second amplifier 203 connected to this rear end. The sixth amplifier 212 also performs this compensating role.

The compensated amplified signal is stripped of adjacent frequency and harmonic signal components by a first surface elastic filter 204. In this case, in order to pass only signals of a desired frequency band, a surface elastic filter having a corresponding center frequency should be selected. In the above example, since the input intermediate frequency signal is 70 MHz, the surface elastic filter having a center frequency of 70 MHz may be selected and mounted. The second surface elastic filter 213 performs the same function and the same tips for selecting the same. In the above example, since the frequency of the signal output by the second down converter 211 is 160 MHz, the surface elastic filter corresponding thereto may be selected.

The output power level of the signal output from the first surface elastic filter 204 is adjusted by the first variable attenuator 205. The second variable attenuator 214 also adjusts the power level of the signal output from the second surface elastic filter 213.

A third amplifier 206 is connected to the rear end of the first variable attenuator 205 to compensate for the filter losses generated by the first surface elastic filter 204. The seventh amplifier 215 plays the same role.

The amplified signal output from the third amplifier 206 is mixed up with the local signal output from the PL synthesizer 219 in the first up-converter 207 and up-converted. At this time, the local signal is a signal having the same frequency as the signal input to the first down converter 202, so that the signal after the conversion has the same frequency as the signal input to the first down converter. For example, if the signal output from the third amplifier 206 is a signal of an intermediate frequency of 70 MHz and the signal frequency output from the PLL synthesizer 219 is 1925 MHz, the output signal of the up-converter 208 is output. The signal has a frequency of 1855 MHz (1925-70 [Mhz]), which is a transmission frequency signal input to the first down converter 202.

The second up-converter 216 also functions as the first up-converter 207. As in the above example, the frequency of the signal output from the seventh amplifier 215 is 160 MHz, and the frequency of the local signal is 1925 MHz. In other words, the signal output from the second up-converter 216 has a frequency of 1765 MHz (1925-160 [MHz]).

A first band pass filter 208 is connected to the rear end of the first up converter to remove the harmonic components generated by the first up converter 207. The second band pass filter 217 is also connected to remove harmonic components generated in the second up-converter 216.

The fourth amplifier 209 and the eighth amplifier 218 amplify the signals output from the first band pass filter 208 and the second band pass filter 217 to an appropriate signal level and finally output them.

The divider 220, which is provided to distribute the local signal generated from the PL synthesizer 219 to the first and second up / down converters 202, 207, 211, and 216, has four paths in this embodiment. A 4-way splitter was used.

Transceiver frequency up / down converter according to the present invention as described above is equipped with only one PLL synthesizer, unlike the conventional converter, due to the simplified circuit improves the reliability of the device and the number of components forming a peripheral circuit is small This reduces the cost of the product, reduces the size of the component circuit, and reduces the power consumption for operating the synthesizer.

Claims (1)

In the transmission and reception frequency up / down converters used in various mobile communication systems, A first amplifier for low noise amplifying the RF signal input at the transmission frequency with a predetermined amplification gain; A first down converter for converting a signal output from the first amplifier into an intermediate frequency; A second amplifier for compensating conversion loss generated during the down conversion; A first surface elastic filter for removing adjacent frequency and harmonics components of the signal output from the second amplifier; A first variable attenuator for appropriately adjusting the power level of the signal output from the first surface elastic filter; A third amplifier connected to an output of the first variable attenuator to compensate for the filter loss generated in the first surface elastic filter; A first upconverter for restoring a signal downconverted by the first downconverter to a signal having an original frequency; A first band pass filter for removing harmonic signals generated during the upconversion; A fourth amplifier for amplifying and finally outputting the band filtered signal; A fifth amplifier for low noise amplifying the RF signal input at the reception frequency with a predetermined amplification gain; A second down converter for converting the signal output from the fifth amplifier to an intermediate frequency; A sixth amplifier for compensating for the conversion loss caused by the down conversion by the second down converter; A second surface elastic filter for removing adjacent frequencies and harmonics components of the signal output from the sixth amplifier; A second variable attenuator for appropriately adjusting the power level of the signal output from the second surface elastic filter; A seventh amplifier connected to an output terminal of the second variable attenuator to compensate for the filter loss generated in the second surface elastic filter; A second upconverter for restoring a signal downconverted by the second downconverter to a signal having an original frequency; A second band pass filter for removing harmonic signals generated during up-conversion by the second upconverter; An eighth amplifier for amplifying and finally outputting the band filtered signal; A PLL synthesizer for providing a local signal mixed during the up / down conversion; And And a splitter for uniformly distributing the local signal output from the PEL synthesizer to each upconverter and downconverter.