?????????????????

???????

??
    ??? ??????????似?????
    1?? ????Χ
    2?? ????Χ?????????????????????fomin????????fomax????仯??Χ,???????????k=fomax/fomin?????k??????????????????????????k>2~3?,??????ο???????????????Ρ????????????,????ε?????????????????????????????
    3??????????????????
???? ???????????????????????????????????????С???,??????????????????????????????????????????,???????????????????????????????????,????????????100Hz,?е??????10Hz??1Hz????0.1Hz??????????????,???????50kHz??25kHz??????Щ??????????,??????????????????????
    4???????????
?????????????????????????????????????????????,??????????????????????????????????????е???????
    5?????????????????
???????????????????????????????涨???????,??????????????????????涨?????????,?????????????涨??????仯???С??
    6?????????
??????????????????????????????????,?????λ????,????????????????λ???????????????????????,????????????????????????????,???10-29?????

?10-29????????????

????(VCO)?淶

??λ????????????????????????????????????￡?????????????????????????????????????????????У????????????????????????????????????????????“??”??Χ???????(????)?????Χ????????????Щ?????????λ????????λ??????????????????????????????????1Hz??????????????????????????????磬??100kHz????-100dBc/Hz????λ?????淶??ζ??????????100kHz????1Hz????????????????????????100dB (?5)??

?5. ????????????????????????????λ??????????

??????????????????????λ?????????????????????????6??????????????????????(LO)???????????????л????????IF???????????????????(??????????????)??????LO???л???????±????IF????Χ????????????????????????λ??????“β??”?????IF????????????????????????????????????????????λ????LO???????????????????????????

?6. ??????????????????±????IF??????????????λ?????????±????????β????????????????????????????????????????

??λ????????????????
??????λ???????????κ????????????????У????????????б?????????????Щ??????????????????????????????е?????????????λ?????????????????????????磬????????￡????????????????????????????????????????λ??????????????????????????????У??????????Щ?????????????????????????????λ?????????????????????????????"?"????????? 8??????Щ??????????λ??????????????????е????????????????????????????????????????????????????λ??????????涨?????????????????????????????????????????? 1Hz ??????????????Щ?????????????????????????????λ???????????λ?????????????????
                 
????????????????????豸????????????????????????????????е?????????????????????????е???λ??????????????????????????????????磬?????????????????????????? 1ps RMS ??????????????????????????????? 7GHz??????????棬??λ?????豸????????????????????????????????????????У??С?? 1ps??????????? 40GHz ??????
??????г??Χ??VCO?????????Χ?????磬VCO???????900MHz?????????????????????г??????????г????850MHz??950MHz???Χ?????????г??Χ??100MHz????????????г??Χ???????涨?????????????Χ??????????Χ??

??г?????VCO?????????г??????????VCO??г???????????磬??г?????50MHz/V??????????г??????1V?????50MHz?????仯????????????г???棬????????????????????·???????????????????и??????λ??????

???????????????????????????????????????????У???????????????????

???????????????????????????????м????????????????????????????????????

???????????????????Щ???????2?????????????????е?????????????

??????????????????????????????仵??????????????????????壬????????????

?????????????????????????????????

         ?? ???????÷?Χ????????

         ?? ???????????

         ?? ??????λ????

         ?? ?????????????

         ?? ?????????????????????

       ?????????????????????????????????????????????????????

????С???μ???λ??????????????

    ?????????????????

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?? ??????????????????????,????????????????????????????????????????
    1???????????????DS????
?????????????????????????????????????????????????????????????,?????????????????????????????????:???????ν??????????;?????????????????
     2.?????????????IS????
?????????????????????????????????????????????????????????????,?????????????????????
??????????????????????е???Щ???,????????????????????????????,??????????????о?????????????????????????????10?D30?????????????????,??λ??????????????????????,??

(10-51)

??

?10-30 ???????????????

VCO??????f0????????

(10-52)

????????????ο????fr????????

(10-53)

????????????????????????????????????????????????????????????鹫??

(10-54)

    ?????????????????????????????,?????????????????????????????????????????????????????????????÷????,????????VCO????????,???10?D31???????÷???????????M,????

(10-55)

???10-31 ????÷?????????????????

?10-32?±????????????

??????????????????????????????????????
(10-56)

    3???????????????????DDS????
???? ???????????????????????????????????????,??????????????,???з???????????????????λ??????????,?????к??????????????????????
???????????Чλ?1?????λ??????,???????????,?????fc????????,??????Nλ???????2N????,???????fc/2N?????????M????????,??DDS?????????

(10-57)

???10-33DDS???????

DDS?????????:??
    ??1????????????,???????,??????????????????????·??????????;??
    ??2????????,??????????,?????????????????N??ο????fc??
    ??3?????任???λ????;??
    ??4???з??С????λ??????
    ??5??????????,?????????????fc??40??????;
    ??6?????к???????????
??PLL?????????,????????????????:??
    ??1????????????????;??
    ??2?????????;??
    ??3????г??Χ???????;??
    ??4????λ?????????????????;??
    ??5?????????????????
DDS????????????DAC?????????????????????????????,????DDS??????????:??
    ??1??????DAC??λ??,DAC??λ???????λ,??????????6dB;??
    ??2????????Ч??λ??,??????λ,??????????10dB;??
    ??3???????????????????????
    DDS??PLL????????????????,????????е????,??????????,???????????????????????????,????????????????????????10?D36??DDS????PLL???????,?????????????DDS????????????????,??DDS?????????????—???PLL,?????????

?10-34DDS????PLL???????

    ?10?D37??AD?????????DDSо?AD70010,??????????20MHz??50MHz????,??λ?????????N=32?????????????????????,??????к??????????,????????????????????????,??AM??PM??FM??ASK??PSK??FSK??MSK??QPSK??QAM???????????

?10-35AD7008???

    ???????????????

??
    1???????????????????
????????????????????????????????10?D32????????е?÷N????????????????????,????????????

(10-58)

    ???fr??ο????,?????????????????????????,?????????????ο??????????????????????????fr????????????????Kd,??·??????????????F??s??,?????????????????K0,??????????????????????????λ???,???10?D38????????, (10-59)

?10-36 ?????????????????λ???

(10-60)

???K′=KdK0/N???????λ????????????,??????????????????????????????ο?????
fr??s??????????fv??s??????????????????

(10-61)

??????????,??????????????????????????????????????????????1??:

??????????????

    ?10-3????a???????????????????L562(NE562)?????????????????????1~10????????????????????10-39??b??

?10-37L562???????
??a??L562?????????(b)L562??????

    2?????????????????????
???? ???????????????????????,VCO?????????????????????????????????????????????????????????,????????????????????????????÷?????????????????????????,?????????????????????????
?10?D????????????????????????????????????????

?10-38 ????????????????

    ??????????????????,?????????????????????V??1,????????????????????V????????????????????????????????,???????????N1??N2,?????м??????????????????????????,????????????

????????????????

??????????????

    ????????????????????

???? ????????????????????????????·????????????????1???????ü????·???????ο?????????ο??????????????????????????????·???????????????????????,??????????????????·??
    1??MC145146??1??
????MC145146??1?????20??????????????,????λ????????????????????????????????????????????????,?10?D41????????????????

?10-39MC145146-1????

??10-4 MC145146-1????????????????????

    ST??12???:???????????,??ST??????,????????D0~D3?????????,ST??????,????????Щ???????
PDout??5???:?????????????????????????fv??fr??fv??λ????,PDout?????????;????λ????,?????????;??fv??fr?????λ?,?????????迹??????
LD??13???:??????????????????????·???????fv??fr?????,???????,?????????????

    ΦV??ΦR(16??17??):?????????????????????????????·??????,???????PDout???????,????????á?
???? ?10?D42?????????????UHF????绰????????????,????????450MHz?? ΦV??ΦR(16??17??):?????????????????????????????·??????,???????PDout???????,????????á?
?????10?D42?????????????UHF????绰????????????,????????450MHz??

?8-40????MC14546-1??UHF???????绰???????

    ?10?D4???????????1000MHz???????????????666??????????????????????绰??????????????????????45MHz,????????11.7MHz,???????????,??????45MHz???ο????fr??7.5kHz,?ο??????R??14100????·??????NT??32*N??A??27501~21011010,N=1059~10100,A=0~31,????VCO??????fv??NTfr??206.2575~211.410MHz??
????MC145145-1??MC145146-1??????,?????????MC145145-1???????????????,?????÷N???????14λ,??N=3??1631010??

?10-41????MC145146-1??800MHZ???????绰???????

    2??MC145151??1??
???? MC145151??1???????14λ????????????????CMOS??LSI??????????????????,????????????10?D4???????

?10-42MCA145151-1 ?????

    MC145151??1??28???????????????·,???????????????????????:??
???? OSCin??OSCout??26??27???:?ο????????????????????
????RA0??RA1??RA2??5??6??7???:?ο??????????
????fin??1???:÷N??????????????
????fv??10???:÷N??????????????
????N0~N13??11??20??22??25???:÷N?????????????
????T??R??21???:???????????

????PDout??4???:PDA???????????
????ΦR??ΦV??10??9???:PDB????????????
????LD??210???:?????????????
?10?D4???????????MC145151??1??????????·??
?10?D4??????????MC145151??1????UHF??????????????????

???????ο???8-5MC145151-1?ο?????????

?10-43 ????MC145151-1??5~5.5MHZ?????·

?10-44????MC145151-1????UHF????????????????

    ??MC145151-1???????MC145152-1,?????????16λ???????????CMOS??LSI??????????????,??????????????MC145151-1?????????MC145151-1??????????,??MC145152-1???????????

?????

?????????????????????????RF IC????????????????????????????????????????????У?????????????????????RF????????????????????

????????????????????????????????????????????????????????????????????????????????????????????????????????????Δ-Σ??????????????????????????????????????????????????????

??????????????????????????(PLL)?????????????????·???????????λ???????ο?????????????????????PLL??ο????????????(PFD)??????(CP)????·??????????????(VCO)??ɡ?

VCO???????PFD????ο?????????λ?????????λ?????????????????????????????????????????????????????????·??????????????????????????????????С????????????????????VCO??г??????????λ??????????????????·??????λ?????У????

PFD??????????????????????????????????PFD????·?????????????????????????????????VCO?????????????·?????????????????????????????ο?????

?????VCO??PLL??????????????PLL???????????????????????ο??????????????????????????????VCO?????????????????N??VCO?????????????????????N????????????????????????????·??÷?????????????ο????????VCO??ο?????N??????fvco=N×fref????fvco???VCO?????????fref????ο?????????????????????????????????????????????????????

??????????????????????????????????????N???????????????????????????????????????????????????N??VCO??????????????????????????????????????????????????????????????fvco??????????N??????????????????????????ο??????????????????????N???????????????????????????????С??????????????fref??????????N?????????????????????

“N??”???????С????????????ο?????????????????????????????????ο????????????????fvco=fref(N+k/M)????k??M??????????M???N??????????????????????????“??????”??“???”??k??0??M???????????????????N+k/M???д??N.F?????????????С????N??F??????????????????С???????

????N????????????????????????N?????????????????????????Ψ????????????????????????????档??????????????????????????????????????Tdo????????Tdo=(N+0.F)Tvco????0.F??????????????Tvco??VCO????????????????????????N??0.F????????????????????????????к????????????????????????N??0.F??VCO?????????????????

????????N??????????Tdo????????ο???????????Tref=(N+0.F)Tvco??fvco=(N+0.F)fref????Tref????ο??????????

????????????????????(DMD)??????????(DLL)????·??????(MUX)?????????λ?????(DPA)???????????????????????????DLL??DLL??????鼶??????????????PD??CP??D???????????DLL?е?????????????????·????????????VCO???????????????????????????????????????VCO?????????Nd??????λ“??”??????Nd????????·??????????????

????DPA?????????????????????òο?????????????????mλ??????????????????????MUX??????????????ο??????????????????x???????x??????mλ??????????DPA?????(???????????λ???)???????1λ??????????????λ??m?????????λ“??”????й????Nd=2m

DPA?????????DMD?????y?λ???????????DMD?????N+1????????λ??????????????N???????????????????????????????DPA?????x?????????N+0.F?????N+x/2m??????DPA??4λ??????????·????8????????????λ“??”????????VCO?????1/8?????????????????2????????0.F?????2/8??????н?λ??????DMD????N??????????????????????PLL??PFD?????????·???????????????????λ??????????????

??????????????DPA??????????????ο?????????2??????????????????ο???????λ?????(0??2??4??6??8)???????????????????????????DMD?????????????2/8??VCO?????????Ч??????N+0.25????????????????Ч??????DPA???????8???DPA??????λ????DMD??????????????·?????????????????????DMD????N+1???λ???????????????DMD????N??????????????8????λ?????(?????VCO????)??

??????

??????????????涨?????????Nd????????????????????????????????·???????????????????VCO??????????????????????????????VCO??????????????