Cov Down Converter COFDM hloov frequency 2.4G rau 600Mhz tsawg BDC

Cov Down Converter

Cov Down Converter COFDM hloov frequency 2.4G rau 600Mhz tsawg

Ntsiab lus muag

1. Input frequencies ntawm 24000 rau 600MHz (Txo 1800Mhz)
2. Bandwidth
3. Theem tsis tshua muaj suab nrov
4. High-frequency stability

Specification (Specification)

RF Frequency Range： 2400 Mhz
YOG TIAS NTAU Yam Kev Pab Ntau Yam： 600 Mhz
Rov qab poob：-12 db
zauv frequency: ±10 ppm
Duab rejection: 60 dBc
flatness: ±0.5 dB (8MHz bandwidth)
Conversion Gain: 25 db
Theem nrov (dBc/Hz)
dBc/Hz@1KHz ≤-80
dBc/Hz@10KHz ≤-90
dBc/Hz@100KHz ≤-100
Mov Voltage: 10£15V
Hwj huam tam sim no: 100 mA
Kev Khiav Hauj Lwm Rau Kev Khiav Hauj Lwm: +25 °C

 

chaw nres nkoj

RF IN: SMA-50K
YOG TAWM MUS: SMA-50K
Hwj huam +12V: lo
GND: Muag lug txhawb cov neeg uas muag

Daim Ntawv Ceeb Toom

1. Tus converter tsis tau ntxiv ib suab nrov amplifier nyob sab nraum qab kawg.
2. Kev Kuaj Mob: Kaw-loop kuaj raws li cov frequency ntawm 2.4GHz/bandwidth 4MHz, Qhov tau txais rhiab yuav mus txog-105dBm.
3. Input frequency txhawb 1.3GHz. (Peb yuav txhawb kev cai dab qhuas).
4. Tso zis frequency txhawb 300.700MHz. (Peb yuav txhawb kev cai dab qhuas).

NQAIJ NYOO

Lus nug: Kuv input frequency ntau yam yuav tsum tau 2.0Ghz rau 2.7Ghz, downconverting rau 200Mhz rau 900Mhz. Cov conversion nce yuav ideally yuav 30db tsis 25db. Qhov no yuav yooj yim rau koj ua?

Teb: Muaj, Peb yuav customize rau koj.

What is DDC

Nyob rau hauv cov teeb liab txheej txheem, Ib cov down-converter (DDC) hloov ib tug digitized, qhab txwv teeb liab rau ib sab frequency teeb liab ntawm ib sab sampling tus nqi thiaj li yuav yooj yim rau cov xov tooj cua tom xov tooj cua theem. Tus txheej txheem preserves tag nrho cov ntaub ntawv nyob rau hauv cov thawj teeb liab tsawg uas yog poob rau rounding yuam kev nyob rau hauv cov txheej txheem mathematical. Cov input thiab tso zis yuav tiag los yog txoj qauv. Feem ntau cov DDC converts ntawm lub xov tooj cua nyoos zaus los yog intermediate zaus mus rau ib txoj baseband teeb liab.

Architecture

Ib DDC consists ntawm peb subcomponents: Ib tug tib neeg synthesizer (.DDS), lim dej tsawg dua (LPF), thiab ib downsampler (uas tej zaum yuav tau integrated rau hauv lub limtiam uas tsis muaj lim dej). Tus DDS generates ib txoj sinusoid ntawm tus intermediate frequency (YOG). Multiplication ntawm tus intermediate frequency nrog lub input teeb liab tsim dluab centered ntawm lub caij ntuj sov thiab txawv zaus (Uas raws li cov frequency shifting zog ntawm tus Plaubier transform). Cov lowpass filters kis tau qhov txawv (i.e. puag) zaus thaum tsis lees txais cov duab summy duab, Uas ua rau ib txoj baseband sawv cev ntawm tus thawj teeb liab. Piv txwv tias judicious xaiv YOG thiab LPF bandwidth, Lub complex baseband teeb liab yog mathematically sib npaug rau cov thawj teeb liab. Nyob rau hauv nws daim ntawv tshiab, Nws yuav npaj tau downsampled thiab yog yooj yim dua rau ntau DSP algorithms. Tej suitable tsawg-kis tau lim dej yuav siv tau xws li FIR, IIR thiab CIC filters. Qhov xaiv feem ntau yog ib lub limtiam FIR filter rau cov uas tsis muaj decimation (tsawg tshaj 100) los yog ib lub limtiam CIC filter raws li ib tug FIR lim dej loj downsampling piv.

Variations rau lub DDC

Ob peb variations rau lub DDC no pab tau, Nrog rau ntau yam uas input ib feedback teeb liab rau hauv lub DDS. Cov no muaj xws li:

1. Kev txiav txim siab qhia rov qab theem muab tub loops uas kuv thiab Q yog piv rau qhov ze zoo tagnrho constellation taw tes ntawm ib PSK teeb liab, thiab qhov uas ua yuam kev yog filtered thiab noj rov qab mus rau hauv lub DDS
2. Ib Costas loop uas cov kuv thiab Q yog multiplied thiab tsawg filtered ua ib feem ntawm ib BPSK/QPSK carrier rov qab loop

Siv
DDCs feem ntau yog DVR hauv logic hauv teb-programmable rooj vag arrays los yog daim ntawv thov integrated circuits. Thaum software siv kuj tau, haujlwm hauv lub DDS, multipliers thiab input theem ntawm lub lowpass filters tag nrho khiav ntawm tus sampling tus nqi ntawm cov ntaub ntawv input. Cov ntaub ntawv no feem ntau noj ncaj qha los ntawm analog rau cov converters converters (ADCs) sampling ntawm kaum los yog 175,000 MHz. CORDICs yog ib lwm txoj rau siv multipliers nyob rau hauv cov kev siv cov converters.

Wireless yees duab transmitter thiab receiver, COFDM-904T pom zoo kom pom zoo.