CN202931311U - Dual conversion structure of digital interphone - Google Patents
Dual conversion structure of digital interphone Download PDFInfo
- Publication number
- CN202931311U CN202931311U CN2012205488516U CN201220548851U CN202931311U CN 202931311 U CN202931311 U CN 202931311U CN 2012205488516 U CN2012205488516 U CN 2012205488516U CN 201220548851 U CN201220548851 U CN 201220548851U CN 202931311 U CN202931311 U CN 202931311U
- Authority
- CN
- China
- Prior art keywords
- capacitor
- resistance
- ground connection
- gain control
- control chip
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired - Fee Related
Links
Images
Landscapes
- Transceivers (AREA)
Abstract
The utility model belongs to the technical field of electronic communication devices, relates to a digital interphone, and particularly relates to a dual conversion structure of the digital interphone. According to the utility model, the dual conversion structure of the digital interphone comprises a mixing circuit, a filter circuit, an amplifier circuit and an AGC (AutomaticGainControl, automatic gain control) circuit; the mixing circuit, the filter circuit, the amplifier circuit and the AGC circuit are connected in order; the AGC circuit is realized through an IF gain control chip and the following circuit; and the dual conversion structure of the digital interphone is used to simplify a dual conversion circuit, so as to reduce the cost of the digital interphone.
Description
Technical field
The utility model belongs to the electronics technical field, relates to digital handset, particularly a kind of double conversion structure of digital handset.
Background technology
At present, the intercom market of China remains analog intercom and occupies an leading position.But analog-interphone exists many shortcomings with not enough: one, what analog-interphone transmitted is analog signal, and signal processing mode is simple, and consumed power is larger, can not effectively eliminate and disturb and the impact of noise, cause that in many situations, speech quality can not be satisfactory; Its two, the frequency efficiency of analog-interphone is not high, channel capacity is low; Its three, the analog-interphone confidentiality is poor, easily is ravesdropping.
In this case, digital handset arises at the historic moment.Digital handset is the digital handset that adopts digital technology to design.Digital handset is with digitization of speech signals, propagate with the digital coding form, that is to say, the whole modulation on the intercom transmission frequency are numeral.Digital handset has many advantages:
1. be at first to utilize better frequency spectrum resource: similar to the cellular digital technology, digital handset can (as 25KHZ) load more users on the channel of an appointment, improve the availability of frequency spectrum, this is a kind of solution that solves frequency congestion, has long-range meaning.
2. be secondly to improve speech quality: because digital communication technology has error correction feature in system, compare with analog-interphone, can in a wider general signal environment, realize better speech audio quality, its audio noise that receives can be less, and sound is more clear.
3. be exactly that raising and improvement voice-and-data are integrated in addition, change control signal and increase the weakness that reduces with communication distance, compare with similar integrated simulation voice and data system, digital handset can provide better data to process and interface function, thereby it is integrated more perfect, convenient to the voice-and-data service that more market demand can be integrated in same bidirectional wireless communication architecture of base station.
Above-mentioned three large characteristics make digital handset become the inexorable trend of following intercom technical development.
The basic principle of digital handset is first analog voice to be converted to digital signal, then is modulated to radio frequency and gets on.Since emission is digital signal, certain this equipment also can directly transmit data.Existing digital handset generally comprises voice transmitting-receiving circuit, radio-frequency (RF) transmit-receive circuit, control circuit, power circuit, digital speech processing module, described digital speech processing module is connected with control circuit, voice transmitting-receiving circuit, power circuit respectively, and is connected with radio-frequency (RF) transmit-receive circuit by analog to digital conversion circuit.Its principle is: utilize the digital speech processing module to carry out digital processing to the baseband analog voice signal, produce digital baseband and transmit, then offer radio-frequency (RF) transmit-receive circuit through digital-to-analogue conversion generation output modulated-analog signal; And demodulated baseband signal is carried out analog-to-digital conversion, and produce digital baseband and receive signal, its processing is obtained audio digital signals, then become the Analog Baseband voice signal through digital-to-analogue conversion, offer loud speaker.
Wherein, radio-frequency (RF) transmit-receive circuit is as core circuit, and the quality of its circuit design affects the performance of whole digital handset.As shown in Figure 1, radio-frequency (RF) transmit-receive circuit comprises the transmitted signal treatment circuit, sends with reference to crystal oscillating circuit, phase-locked loop circuit, preamplifying circuit, power amplifier, RAMP control circuit, transmit-receive switch commutation circuit, transceiver channel filtering and antenna-matching circuit, double conversion circuit, high intermediate frequency filter circuit, receives mixting circuit and electrically regulated filtering and LNA circuit etc.Wherein, the double conversion circuit structure in order to functions such as mixing, filtering, amplification, automatic gain controls is the most important thing.And the general use of existing double conversion structure is that the partial circuit that high price I/Q solution is called IC is controlled, with high costs, expensive, is not suitable for large-scale promotion.
The utility model content
Technical problem to be solved in the utility model is, a kind of double conversion structure of digital handset is provided, adopt IF gain control chip and peripheral circuit to replace existing high price I/Q solution to call IC, reduce costs, so that digital handset is able to large-scale promotion.
In order to solve the problems of the technologies described above, the double conversion structure of a kind of digital handset of the utility model, comprise mixting circuit, filter circuit, amplifying circuit and AGC(Automatic Gain Control, automatic gain is controlled) circuit, mixting circuit, filter circuit, amplifying circuit are connected with agc circuit and are connected.Wherein, agc circuit is to be realized by IF gain control chip and follow circuit thereof.
concrete, this double conversion structure comprises: IF gain control chip A1, triode V1, filter A2, the first filter A3, the second filter A4, inductance L 47, inductance L 48, inductance L 49, inductance L 50, capacitor C 15, capacitor C 16, capacitor C 17, capacitor C 18, capacitor C 19, capacitor C 20, capacitor C 21, capacitor C 22, capacitor C 23, capacitor C 24, capacitor C 25, capacitor C 26, capacitor C 27, capacitor C 28, capacitor C 29, capacitor C 30, capacitor C 31, capacitor C 32, capacitor C 33, capacitor C 34, capacitor C 35, capacitor C 36, capacitor C 37, capacitor C 38, resistance R 11, resistance R 12, resistance R 13, resistance R 14, resistance R 15, resistance R 16, resistance R 17, resistance R 18, resistance R 19, resistance R 21, the ICFDBC pin of IF gain control chip A1 is by capacitor C 20 ground connection, the ICFIN+ pin of IF gain control chip A1 is connected to an end and resistance R 14 1 ends of capacitor C 15, the other end ground connection of resistance R 14, the other end ground connection of capacitor C 15 by capacitor C 19, the GND1 pin ground connection of IF gain control chip A1, the MDOUT pin of IF gain control chip A1 connects the end of filter A2 and an end of resistance R 11 by capacitor C 18, the other end ground connection of resistance R 11, the other end of filter A2 connects an end of capacitor C 17 and an end of resistance R 12 by resistance R 13, the other end ground connection of resistance R 12, the other end of capacitor C 17 connect the IFIN pin of IF gain control chip A1, the GND2 pin ground connection of IF gain control chip A1, the IFDBC pin of IF gain control chip A1 is by capacitor C 16 ground connection, the OCIN pin of IF gain control chip A1 connects an end of capacitor C 23, an end and the power supply of capacitor C 24, the other end ground connection of the other end of capacitor C 23 and capacitor C 24, the IFOUT pin of IF gain control chip A1 is by the end of capacitor C 25 contact resistance R16 and an end of inductance L 50, the other end ground connection of resistance R 16, the other end of inductance L 50 is drawn Low Medium Frequency signal 455KHz by a signal line by capacitor C 38 ground connection between inductance L 50 and capacitor C 38, the RSS pin of IF gain control chip A1 is by capacitor C 26 ground connection, the V+2 pin of IF gain control chip A1 connects an end, an end of capacitor C 28 and an end of resistance R 18 of capacitor C 27, the V+1 pin of IF gain control chip A1 connects the end of C29, an end of capacitor C 30, an end of resistance R 17, the other end ground connection of the other end of the other end of capacitor C 27, capacitor C 28, the other end of C29 and capacitor C 30 is connected to the second filter A4 after the other end of the other end of resistance R 18 and resistance R 17 is connected, the LOIN pin of IF gain control chip A1 is by the end of capacitor C 22 contact resistance R15, one end of capacitor C 33, one end of capacitor C 34 and an end of inductance L 49, the other end ground connection of the other end of resistance R 15 and capacitor C 33, the other end of capacitor C 34 connects the other end of inductance L 49, one end of capacitor C 35, one end of capacitor C 31, the other end ground connection of capacitor C 35, the other end of capacitor C 31 connects an end of inductance L 48, one end of inductance L 47, one end of resistance R 21 and the C utmost point of triode V1, the other end of inductance L 48 is by capacitor C 32 ground connection, the other end of inductance L 47 connects an end of capacitor C 37, one end of resistance R 19, the other end ground connection of capacitor C 37, the other end of resistance R 19 is connected to the first filter A3, the B utmost point of the other end connecting triode V1 of electric capacity R21 and an end of capacitor C 36, the other end of capacitor C 36 connects external intermediate-freuqncy signal by resistance R 20, the E utmost point ground connection of triode V1, the LODBC pin of IF gain control chip A1 is by capacitor C 21 ground connection.
As a further technical scheme, described IF gain control chip A1 is that the employing model is the IF gain control chip of NJM2287.It is the ceramic filter of 455G that described filter A2 adopts model.It is the EMI inhibition filter of the On-Board type (DC) of BLM15AG121SN1 that described the first filter A3 and/or the second filter A4 adopt model.
The utility model replaces existing high price I/Q solution to call IC by such scheme with IF gain control chip NJM2287 and peripheral circuit, has reduced cost, thereby can make digital handset be able to large-scale promotion.
Description of drawings
Fig. 1 is the circuit block diagram of radio-frequency (RF) transmit-receive circuit of the prior art.
Fig. 2 is the schematic diagram of radio-frequency (RF) transmit-receive circuit of the prior art.
Fig. 3 is the circuit theory diagrams of double conversion structure of the present utility model.
Embodiment
Now with embodiment, the utility model is further illustrated by reference to the accompanying drawings.
As depicted in figs. 1 and 2, radio-frequency (RF) transmit-receive circuit generally comprises the transmitted signal treatment circuit, sends with reference to crystal oscillating circuit, phase-locked loop circuit, preamplifying circuit, power amplifier, RAMP control circuit, transmit-receive switch commutation circuit, transceiver channel filtering and antenna-matching circuit, double conversion circuit, high intermediate frequency filter circuit, receives mixting circuit and electrically regulated filtering and LNA circuit etc.The utility model improves mainly for the structure of double conversion circuit.Concrete, this double conversion structure comprises mixting circuit, filter circuit, amplifying circuit and AGC(Automatic Gain Control, automatic gain is controlled) and circuit, mixting circuit, filter circuit, amplifying circuit are connected with agc circuit and are connected.Wherein, agc circuit is to be realized by IF gain control chip and follow circuit thereof.
as specific embodiment of the utility model, as shown in Figure 3, a kind of double conversion structure of digital handset, comprise: IF gain control chip A1, triode V1, filter A2, the first filter A3, the second filter A4, inductance L 47, inductance L 48, inductance L 49, inductance L 50, capacitor C 15, capacitor C 16, capacitor C 17, capacitor C 18, capacitor C 19, capacitor C 20, capacitor C 21, capacitor C 22, capacitor C 23, capacitor C 24, capacitor C 25, capacitor C 26, capacitor C 27, capacitor C 28, capacitor C 29, capacitor C 30, capacitor C 31, capacitor C 32, capacitor C 33, capacitor C 34, capacitor C 35, capacitor C 36, capacitor C 37, capacitor C 38, resistance R 11, resistance R 12, resistance R 13, resistance R 14, resistance R 15, resistance R 16, resistance R 17, resistance R 18, resistance R 19, resistance R 21, the first pin of IF gain control chip A1 is by capacitor C 20 ground connection, the second pin of IF gain control chip A1 is connected to an end and resistance R 14 1 ends of capacitor C 15, the other end ground connection of resistance R 14, the other end ground connection of capacitor C 15 by capacitor C 19, the 3rd pin ground connection of IF gain control chip A1, the 4th pin of IF gain control chip A1 connects the end of filter A2 and an end of resistance R 11 by capacitor C 18, the other end ground connection of resistance R 11, the other end of filter A2 connects an end of capacitor C 17 and an end of resistance R 12 by resistance R 13, the other end ground connection of resistance R 12, the other end of capacitor C 17 connect the 6th pin of IF gain control chip A1, the 5th pin ground connection of IF gain control chip A1, the 7th pin of IF gain control chip A1 is by capacitor C 16 ground connection, the 8th pin of IF gain control chip A1 connects an end of capacitor C 23, an end and the power supply of capacitor C 24, the other end ground connection of the other end of capacitor C 23 and capacitor C 24, the 9th pin of IF gain control chip A1 is by the end of capacitor C 25 contact resistance R16 and an end of inductance L 50, the other end ground connection of resistance R 16, the other end of inductance L 50 is drawn Low Medium Frequency signal 455KHz by a signal line by capacitor C 38 ground connection between inductance L 50 and capacitor C 38, the tenth pin of IF gain control chip A1 is by capacitor C 26 ground connection, the 11 pin of IF gain control chip A1 connects an end, an end of capacitor C 28 and an end of resistance R 18 of capacitor C 27, the 12 pin of IF gain control chip A1 connects the end of C29, an end of capacitor C 30, an end of resistance R 17, the other end ground connection of the other end of the other end of capacitor C 27, capacitor C 28, the other end of C29 and capacitor C 30, be connected to the second filter A4 after the other end of the other end of resistance R 18 and resistance R 17 is connected, the signal end of the second filter A4 connects outer signal (high intermediate frequency filter circuit), the 13 pin of IF gain control chip A1 is by the end of capacitor C 22 contact resistance R15, one end of capacitor C 33, one end of capacitor C 34 and an end of inductance L 49, the other end ground connection of the other end of resistance R 15 and capacitor C 33, the other end of capacitor C 34 connects the other end of inductance L 49, one end of capacitor C 35, one end of capacitor C 31, the other end ground connection of capacitor C 35, the other end of capacitor C 31 connects an end of inductance L 48, one end of inductance L 47, one end of resistance R 21 and the C utmost point of triode V1, the other end of inductance L 48 is by capacitor C 32 ground connection, the other end of inductance L 47 connects an end of capacitor C 37, one end of resistance R 19, the other end ground connection of capacitor C 37, the other end of resistance R 19 connects the first filter A3, the signal end of the first filter A3 connects outer signal (high intermediate frequency filter circuit), the B utmost point of the other end connecting triode V1 of electric capacity R21 and an end of capacitor C 36, the other end of capacitor C 36 connects external intermediate-freuqncy signal (16.8MHZ) by resistance R 20, the E utmost point ground connection of triode V1, the 14 pin of IF gain control chip A1 is by capacitor C 21 ground connection.
Above-mentioned IF gain control chip A1 is that the employing model is the IF gain control chip of NJM2287, it is the ceramic filter of 455G that filter A2 adopts model, and it is the EMI inhibition filter of the On-Board type (DC) of BLM15AG121SN1 that the first filter A3 and the second filter A4 all adopt model.
In whole radio-frequency (RF) transmit-receive circuit, the double conversion structure mainly realizes mixing, filtering, amplification and AGC function, signal process transmit-receive switch commutation circuit, electrically regulated filtering and the LNA circuit specifically inputted from antenna, again through receiving the high intermediate frequency filter circuit of mixing, enter the reception mixting circuit and carry out mixing, will be from the amplifying signal of radio frequency and local oscillation signal mixing from phase-locked loop circuit, and finally export Low Medium Frequency signal 455KHz.The utility model provides cost savings because adopting said structure, has simplified the available circuit structure, has good practicality.
Although specifically show and introduced the utility model in conjunction with preferred embodiment; but the those skilled in the art should be understood that; within not breaking away from the spirit and scope of the present utility model that appended claims limits; can make a variety of changes the utility model in the form and details, be protection range of the present utility model.
Claims (5)
1. the double conversion structure of a digital handset, it is characterized in that: comprise mixting circuit, filter circuit, amplifying circuit and agc circuit, described mixting circuit, filter circuit, amplifying circuit are connected with agc circuit and are connected.
2. the double conversion structure of a kind of digital handset according to claim 1, it is characterized in that: this double conversion structure comprises: IF gain control chip A1, triode V1, filter A2, the first filter A3, the second filter A4, inductance L 47, inductance L 48, inductance L 49, inductance L 50, capacitor C 15, capacitor C 16, capacitor C 17, capacitor C 18, capacitor C 19, capacitor C 20, capacitor C 21, capacitor C 22, capacitor C 23, capacitor C 24, capacitor C 25, capacitor C 26, capacitor C 27, capacitor C 28, capacitor C 29, capacitor C 30, capacitor C 31, capacitor C 32, capacitor C 33, capacitor C 34, capacitor C 35, capacitor C 36, capacitor C 37, capacitor C 38, resistance R 11, resistance R 12, resistance R 13, resistance R 14, resistance R 15, resistance R 16, resistance R 17, resistance R 18, resistance R 19, resistance R 21, the ICFDBC pin of IF gain control chip A1 is by capacitor C 20 ground connection, the ICFIN+ pin of IF gain control chip A1 is connected to an end and resistance R 14 1 ends of capacitor C 15, the other end ground connection of resistance R 14, the other end ground connection of capacitor C 15 by capacitor C 19, the GND1 pin ground connection of IF gain control chip A1, the MDOUT pin of IF gain control chip A1 connects the end of filter A2 and an end of resistance R 11 by capacitor C 18, the other end ground connection of resistance R 11, the other end of filter A2 connects an end of capacitor C 17 and an end of resistance R 12 by resistance R 13, the other end ground connection of resistance R 12, the other end of capacitor C 17 connect the IFIN pin of IF gain control chip A1, the GND2 pin ground connection of IF gain control chip A1, the IFDBC pin of IF gain control chip A1 is by capacitor C 16 ground connection, the OCIN pin of IF gain control chip A1 connects an end of capacitor C 23, an end and the power supply of capacitor C 24, the other end ground connection of the other end of capacitor C 23 and capacitor C 24, the IFOUT pin of IF gain control chip A1 is by the end of capacitor C 25 contact resistance R16 and an end of inductance L 50, the other end ground connection of resistance R 16, the other end of inductance L 50 is drawn Low Medium Frequency signal 455KHz by a signal line by capacitor C 38 ground connection between inductance L 50 and capacitor C 38, the RSS pin of IF gain control chip A1 is by capacitor C 26 ground connection, the V+2 pin of IF gain control chip A1 connects an end, an end of capacitor C 28 and an end of resistance R 18 of capacitor C 27, the V+1 pin of IF gain control chip A1 connects the end of C29, an end of capacitor C 30, an end of resistance R 17, the other end ground connection of the other end of the other end of capacitor C 27, capacitor C 28, the other end of C29 and capacitor C 30 is connected to the second filter A4 after the other end of the other end of resistance R 18 and resistance R 17 is connected, the LOIN pin of IF gain control chip A1 is by the end of capacitor C 22 contact resistance R15, one end of capacitor C 33, one end of capacitor C 34 and an end of inductance L 49, the other end ground connection of the other end of resistance R 15 and capacitor C 33, the other end of capacitor C 34 connects the other end of inductance L 49, one end of capacitor C 35, one end of capacitor C 31, the other end ground connection of capacitor C 35, the other end of capacitor C 31 connects an end of inductance L 48, one end of inductance L 47, one end of resistance R 21 and the C utmost point of triode V1, the other end of inductance L 48 is by capacitor C 32 ground connection, the other end of inductance L 47 connects an end of capacitor C 37, one end of resistance R 19, the other end ground connection of capacitor C 37, the other end of resistance R 19 is connected to the first filter A3, the B utmost point of the other end connecting triode V1 of electric capacity R21 and an end of capacitor C 36, the other end of capacitor C 36 connects external intermediate-freuqncy signal by resistance R 20, the E utmost point ground connection of triode V1, the LODBC pin of IF gain control chip A1 is by capacitor C 21 ground connection.
3. the double conversion structure of a kind of digital handset according to claim 2 is characterized in that: described IF gain control chip A1 is that to adopt model be the IF gain control chip of NJM2287.
4. the double conversion structure of a kind of digital handset according to claim 2 is characterized in that: it is the ceramic filter of 455G that described filter A2 adopts model.
5. the double conversion structure of a kind of digital handset according to claim 2 is characterized in that: it is that the EMI of BLM15AG121SN1 suppresses filter that described the first filter A3 and/or the second filter A4 adopt model.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN2012205488516U CN202931311U (en) | 2012-10-25 | 2012-10-25 | Dual conversion structure of digital interphone |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN2012205488516U CN202931311U (en) | 2012-10-25 | 2012-10-25 | Dual conversion structure of digital interphone |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN202931311U true CN202931311U (en) | 2013-05-08 |
Family
ID=48221220
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN2012205488516U Expired - Fee Related CN202931311U (en) | 2012-10-25 | 2012-10-25 | Dual conversion structure of digital interphone |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN202931311U (en) |
-
2012
- 2012-10-25 CN CN2012205488516U patent/CN202931311U/en not_active Expired - Fee Related
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN111431584B (en) | Satellite mobile communication terminal based on radio frequency transceiver chip module | |
| CN203608193U (en) | Hand-held short-wave radio station based on radio frequency digitalization | |
| CN202334505U (en) | Airborne ultra-short wave radio station | |
| CN202978934U (en) | CMMB digital micropower repeater | |
| CN105119628A (en) | Frequency-selecting device of ARC digital intercom system | |
| CN204290955U (en) | A kind of digital handset | |
| CN202931311U (en) | Dual conversion structure of digital interphone | |
| CN204177972U (en) | Beidou satellite navigation single/double mode hand-hold radio frequency component | |
| CN201365288Y (en) | Mobile telephone | |
| CN204615817U (en) | A kind of micro power radio module | |
| CN202931312U (en) | Mixing receiving circuit of digital interphone | |
| CN101938292B (en) | Multimode multi-standard mobile phone radio frequency transceiver | |
| CN201813397U (en) | Wireless data communication module | |
| CN208904993U (en) | A kind of double-channel wireless broadband transmission equipment | |
| CN109525261A (en) | FM receives circuit | |
| CN203261347U (en) | Multichannel wireless audio transmission system | |
| CN103414490A (en) | Wireless telecom equipment with reconfigurable carrier frequency and reconfigurable signal bandwidth | |
| CN202696917U (en) | WLAN (wireless local area network) wireless access point equipment | |
| CN202931264U (en) | Electric tuning filter and LNA circuit of digital interphone | |
| CN107911808B (en) | Communication system and communication method for realizing analog talkback based on mobile phone terminal | |
| CN202931284U (en) | Phase-locked loop circuit of digital interphone | |
| CN203086452U (en) | Digital wireless intercommunicating system | |
| CN204462383U (en) | A kind of radio radar system pattern-band transmitter chip structure and radiating circuit | |
| CN201503628U (en) | GSM remote saving alarm | |
| CN203278759U (en) | Two-stage automatic gain control circuit with compensation function |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| C14 | Grant of patent or utility model | ||
| GR01 | Patent grant | ||
| CF01 | Termination of patent right due to non-payment of annual fee |
Granted publication date: 20130508 Termination date: 20141025 |
|
| EXPY | Termination of patent right or utility model |