ADMV4420的K波段下變換器解決方案

ADI公司的ADMV4420是集成了分?jǐn)?shù)－N PLL和VCO的K波段下變換器，具有高度集成雙平衡有源混頻器和分?jǐn)?shù)N合成器，其RF前端包括集成的平衡/不平衡變換器（balun）和低噪音放大器（LNA）（7dB單邊帶噪音），以及高動(dòng)態(tài)范圍IF輸出放大器，其轉(zhuǎn)換增益36dB.集成的低相位噪音分?jǐn)?shù)N鎖相環(huán)（PLL）和多核壓控振蕩器（VCO）和內(nèi)部2x乘法器，輸出P1dB為7 dBm，輸出IP3為16 dBm，RF輸入頻率16.95 GHz 到 22.05 GHz， LO頻率范圍16.75 GHz to 21.15 GHz， IF頻率范圍900 MHz 到 2500 MHz ，5V工作電壓，主要用在衛(wèi)星通信和點(diǎn)對(duì)點(diǎn)微波通信。本文介紹了ADMV4420主要特性，功能框圖以及評(píng)估板ADMV4420-EVALZ主要特性，配置圖和實(shí)驗(yàn)室連接圖，電路圖，材料清單和PCB設(shè)計(jì)圖。

The ADMV4420 is a highly integrated， double balanced， active mixer with an integrated fractional-N synthesizer， ideally suited for next generation K band satellite communications.

The RF front end consists of an integrated RF balun and low noise amplifier （LNA） for an optimal， 7 dB， single-sideband noise figure while minimizing external components. Additionally， the high dynamic range IF output amplifier provides a nominal conversion gain of 36 dB.

An integrated low phase noise， fractional-N， phase-locked loop （PLL） with a multicore voltage controlled oscillator （VCO） and internal 2× multiplier generate the necessary on-chip LO signal for the double balanced mixer， eliminating the need for external frequency synthesis. The multicore VCO uses an internal autocalibration routine that allows the PLL to select the necessary settings and lock in approximately 400 μs.

The reference input to the PLL employs a differentially excited 50 MHz crystal oscillator. Alternatively， the reference input can be driven by an external， singled-ended， 50 MHz source. The phase frequency detector （PFD） comparison frequency of the PLL operates up to 50 MHz.

The ADMV4420 is fabricated on a silicon germanium （SiGe）， bipolar complementary metal-oxide semiconductor （BiCMOS） process， and is available in a 32-lead， RoHS compliant， 5 mm × 5 mm LFCSP package with an exposed pad. The device is specified over the ?40°C to +85°C temperature range on a 5 V power supply.

ADMV4420主要特性：

RF front end with integrated RF balun and LNA

Double balanced， active mixer with high dynamic range IF amplifier

Fractional-N synthesizer with low phase noise， multicore VCO

5 V supply operation with integrated LDO regulators

Output P1dB： 7 dBm

Output IP3： 16 dBm

Conversion gain： 36 dB

Noise figure： 7 dB

RF input frequency range： 16.95 GHz to 22.05 GHz

Internal LO frequency range： 16.75 GHz to 21.15 GHz

IF frequency range： 900 MHz to 2500 MHz

Single-ended 50 Ω input impedance and 75 Ω IF output impedance

Programmable via 4-wire SPI

32-lead， 5 mm × 5 mm LFCSP

ADMV4420應(yīng)用：

Satellite communication

Point to point microwave communication

圖1. ADMV4420功能框圖

評(píng)估板ADMV4420-EVALZ

The ADMV4420-EVALZ evaluation board can be used to evaluate the performance of the ADMV4420. The top and cross sectional layout views of the ADMV4420-EVALZ evaluation board are shown in Figure 126 and Figure 127， respectively. The RF transmission lines were designed using a coplanar waveguide （CPWG） model with a line width （W） of 16 mil and 13 mil of ground spacing for a characteristic impedance of 50Ω for the RF input （RFIN） and the external reference input （REF/XTAL1）。 The line width and ground spacing for the IF output （IFOUT） are 9 mil and 15 mil， respectively. The PCB is made with Rogers 4350B dielectric material， which offers low loss performance， and isola 370HR dielectric material， which achieves the required thickness of the PCB.

The ADMV4420-EVALZ comes with an ADMV4420 chip. Figure 4 shows the location of this chip on the evaluation board and the block diagram of the ADMV4420.

When evaluating the device， connect the RF input to an RF signal generator. The ADMV4420-EVALZ runs on a 5 V dc supply. Figure 2 shows the top side of the ADMV4420-EVALZ and is intended for evaluation purposes only.

Connect the 5 V dc to the VPOS1 test point and ground to the GND2 test point on the ADMV4420-EVALZ. Connect a 50 Ω SMA female to a 75 Ω Type F male adapter to J4 （IF output）。 Connect the output of the adapter to a spectrum analyzer. The ADMV4420-EVALZ has 50 MHz crystal on board. Optionally， the user can connect a reference signal from a low phase signal generator to the J2 SMA connector. If the user wants to use an external reference， depopulate Y1， C5， and C6 and then install a 0.01 μF capacitor at C21， a 1 nF capacitor at C6， and 50 Ω at R21. See Figure 5 for ADMV4420-EVALZ lab connections. Figure 3 shows the block diagram of the ADMV4420 lab bench setup.

評(píng)估板ADMV4420-EVALZ主要特性：

Full feature evaluation board for the ADMV4420

On-board SDP-S connector for SPI control

5 V operation

ACE software interface for SPI control

圖2. 評(píng)估板ADMV4420-EVALZ外形圖

圖3. 評(píng)估板ADMV4420-EVALZ電路圖

評(píng)估板ADMV4420-EVALZ材料清單：

圖4. 評(píng)估板ADMV4420-EVALZ配置圖

圖5. 評(píng)估板ADMV4420-EVALZ實(shí)驗(yàn)室連接圖

圖6. 評(píng)估板ADMV4420-EVALZ 18GHz RF信號(hào)，17GHz LO和50MHz板上晶振設(shè)定圖

圖7. 評(píng)估板ADMV4420-EVALZ 18GHz RF信號(hào)，20.2GHz LO和50MHz板上晶振設(shè)定圖

圖8. 評(píng)估板ADMV4420-EVALZ 頂視圖

圖9. 評(píng)估板ADMV4420-EVALZ 底視圖

圖10. 評(píng)估板ADMV4420-EVALZ PCB頂視圖

圖11. 評(píng)估板ADMV4420-EVALZ實(shí)驗(yàn)室工作臺(tái)建立框圖

圖12. 評(píng)估板ADMV4420-EVALZ 布局圖（頂視圖1）

圖12. 評(píng)估板ADMV4420-EVALZ 布局圖（層2）

圖13. 評(píng)估板ADMV4420-EVALZ 布局圖（層3）

圖14. 評(píng)估板ADMV4420-EVALZ 布局圖層4（底面）

詳情請(qǐng)見：

https://www.analog.com/media/en/technical-documentation/data-sheets/ADMV4420.pdf

和

https://www.analog.com/media/en/technical-documentation/user-guides/ADMV4420-EVALZ-UG-1404.pdf

ADMV4420.pdf

ADMV4420-EVALZ-UG-1404.pdf