原标题：RF无线通讯

应用领域：通信广电

方案类型：模块板卡

主控芯片：SI44**

方案概述

1、低成本RF无线组网。

2、中远距离通讯(≤1km)。

3、UART接口。

4、干接点输入。

5、与公司自有的ZIGBEE/BLE/Lora/物联网等无线模块兼容替代。

6、适用于低成本中远距无线通讯、工业控制等。

【Si4438】

HIGH-PERFORMANCE, LOW-CURRENT TRANSCEIVER

Features

> Frequency range = 425–525 MHz

> Receive sensitivity = –124 dBm

> Modulation

》(G)FSK

》OOK

> Max output power

》+20 dBm

> Low active power consumption

》14 mA RX

> Ultra low current powerdown modes

》30 nA shutdown, 50 nA standby

> Data rate = 100 bps to 500 kbps

> Fast wake and hop times

> Power supply = 1.8 to 3.6 V

> Excellent selectivity performance

》58 dB adjacent channel

》75 dB blocking at 1 MHz

> Antenna diversity and T/R switch control

> Highly configurable packet handler

> TX and RX 64 byte FIFOs

> Auto frequency control (AFC)

> Automatic gain control (AGC)

> Low BOM

> Low battery detector

> Temperature sensor

> 20-Pin QFN package

> IEEE 802.15.4g ready

> China regulatory

Applications

> China smart meters

Description

Silicon Laboratories' Si4438 is a high-performance, low-currenttransceivers covering the sub-GHz frequency bands from 425 to525 MHz. The Si4438 is targeted at the Chinese smart meter market andis especially suited for electric meters. This device is footprint- andpin-compatible with the Si446x radios, which provide industry-leadingperformance for worldwide sub-GHz applications. The radios are part ofthe EZRadioPRO® family, which includes a complete line of transmitters,receivers, and transceivers covering a wide range of applications. Allparts offer outstanding sensitivity of –124 dBm while achieving extremelylow active and standby current consumption. The 58 dB adjacent channelselectivity with 12.5 kHz channel spacing ensures robust receiveoperation in harsh RF conditions. The Si4438 offers exceptional outputpower of up to +20 dBm with outstanding TX efficiency. The high outputpower and sensitivity results in an industry-leading link budget of 144 dBallowing extended ranges and highly robust communication links.

Functional Block Diagram

【Si446x】

Si446x/Si4362 RX LNA Matching

1. Introduction

The purpose of this application note is to provide a description of the impedance matching of the RX differential lownoise amplifier (LNA) on the Si446x/Si4362 family of RFICs.

It is desired to simultaneously achieve two goals with the matching network:

>Match the LNA input to the antenna source impedance (e.g., 50 

>Provide a single-ended-to-differential conversion function (i.e., a balun)

The matching procedure outlined in this document provides for achieving the goals listed above.For those users who are not interested in the theoretical derivation of the match network, but are just concernedwith quickly obtaining matching component values, refer to the Summary Tables shown in "4.1.7. Summary Tablesof 3-Element Match Network Component Values vs. Frequency" on page 12 and "4.2.7. Summary Tables of 4-Element Match Network Component Values vs. Frequency" on page 19.

Measurements were performed on the Si4461-B0 chip but are applicable to other members of the Si446x family ofchips (e.g. Si446x-B1, C0, C1, C2 and the Si4362 chip).

2. Match Network Topology

The LNA on the Si446x/Si4362 family of chips is designed as a differential amplifier and thus has two input pins(RXp and RXn) on the RFIC. It is necessary to design a network that not only provides a conjugate match to theinput impedance of the LNA but also provides a balanced-to-unbalanced conversion function (i.e., a balun).

The LNA design is differential and thus the RXp and the RXn input pins may be considered interchangeable.Although the figures in this document may show the matching components connected to the RXp/RXn pins in acertain fashion, the pin connections may be reversed without change in functionality.Use of two basic matching network topologies will be considered within this application note.

2.1. Three-Element Match Network

The simplest match network that may be fabricated from discrete components is comprised of three discreteelements. Two forms of the 3-element match network may be constructed: one with a highpass filter (HPF)response, and one with a lowpass filter (LPF) response. However, the form with a lowpass filter response is notrealizable at all frequencies and input impedances. As a result, only the form with a highpass filter response isdiscussed within this document.

A 3-element (CR1-LR1-CR2) HPF matching network is shown in Figure 1. This matching network has the virtue ofrequiring a minimum number of components but results in slightly sub-optimal performance. It is not theoreticallypossible to achieve a perfectly balanced single-ended-to-differential conversion function with this matching networkfor input impedances with finite values of RLNA. As will be demonstrated, the waveforms obtained at the RXp and RXn inputs to the RFIC will not be exactly 180° out of phase; the result is a very slight loss in conversion gain in the LNA and a small drop in overall sensitivity of the RFIC. The reduction in performance is typically less than 0.5 dB;many customers may view this as an acceptable trade-off for the reduction in the bill of materials (BOM).

The RXp and RXn inputs of the Si446x/Si4362 RX LNA internally contain high value (~15 k) pull-down resistorsto GND. As a result, supplying a DC voltage to these pins is not recommended; use of external AC-coupling to these pins is suggested. This is inherently supplied by capacitor CR2 of Figure 1.

Si4463/Si4461/Si4460-C

Features

> Frequency range = 142–1050 MHz

> Receive sensitivity = –129 dBm

> Modulation

》(G)FSK, 4(G)FSK, (G)MSK

》OOK

> Max output power

》+20 dBm (Si4463)

》+16 dBm (Si4461)

》+13 dBm (Si4460)

> PA support for +27 or +30 dBm

> Low active power consumption

》10/13 mA RX

》18 mA TX at +10 dBm (Si4460)

> Ultra low current powerdown modes

》30 nA shutdown, 40 nA standby

> Preamble sense mode

》6 mA average RX current at

1.2 kbps

》10 µA average RX current at

50 kbps and 1 sec sleep interval

> Fast preamble detection

》1 byte preamble detection

> Data rate = 100 bps to 1 Mbps

> Fast wake and hop times

> Power supply = 1.8 to 3.8 V

> Excellent selectivity performance

》69 dB adjacent channel

》79 dB blocking at 1 MHz

> Antenna diversity and T/R switch control

> Highly configurable packet handler

> TX and RX 64 byte FIFOs

》129 bytes dedicated Tx or Rx

> Auto frequency control (AFC)

> Automatic gain control (AGC)

> Low BOM

> Low battery detector

> Temperature sensor

> 20-Pin QFN package

> IEEE 802.15.4g and WMBus compliant

> Suitable for FCC Part 90 Mask D, FCCpart 15.247, 15,231, 15,249, ARIB T-108,T-96, T-67, RCR STD-30, China

regulatory

> ETSI Category I Operation EN300 220

Applications

> Smart metering (802.15.4g and WMBus)

> Remote control

> Home security and alarm

> Telemetry

> Garage and gate openers

> Remote keyless entry

> Home automation

> Industrial control

> Sensor networks

> Health monitors

> Electronic shelf labels

Description

Silicon Laboratories' Si446x devices are high-performance, low-currenttransceivers covering the sub-GHz frequency bands from 142 to 1050 MHz. Theradios are part of the EZRadioPRO® family, which includes a complete line oftransmitters, receivers, and transceivers covering a wide range of applications. Allparts offer outstanding sensitivity of –129 dBm while achieving extremely lowactive and standby current consumption. The Si4463/61/60 offers frequencycoverage in all major bands. The Si446x includes optimal phase noise, blocking,and selectivity performance for narrow band and wireless MBus licensed bandapplications, such as FCC Part90 and 169 MHz wireless Mbus. The 69 dBadjacent channel selectivity with 12.5 kHz channel spacing ensures robustreceive operation in harsh RF conditions, which is particularly important for narrowband operation. The Si4463 offers exceptional output power of up to +20 dBmwith outstanding TX efficiency. The high output power and sensitivity results in anindustry-leading link budget of 146 dB allowing extended ranges and highly robustcommunication links. The Si4460 active mode TX current consumption of 18 mAat +10 dBm and RX current of 10 mA coupled with extremely low standby currentand fast wake times ensure extended battery life in the most demandingapplications. The Si4463 can achieve up to +27 dBm output power with built-inramping control of a low-cost external FET. The devices can meet worldwideregulatory standards: FCC, ETSI, wireless MBus, and ARIB. All devices aredesigned to be compliant with 802.15.4g and WMbus smart metering standards.

The devices are highly flexible and can be configured via the WirelessDevelopment Suite (WDS) available on the Silicon Labs website.

【Si4460】

Silicon Labs 的 EZRadioPRO 设备是高性能的低电流收发器，其覆盖了 119–1050 MHz 的 Sub-GHz 频段。这些收音机是 EZRadioPRO 系列的一部分，该系列包含覆盖各种应用的完整发射器、接收器和收发器产品线。EZRadioPRO 具有高达 -133 dBm 的出色灵敏度，同时实现极低的工作和待机电流消耗。此设备通过其集成片上 PA 展现出高达 +20 dBm 的卓越输出功率(活动模式 TX 电流消耗)。还包括唤醒定时器、低电量探测器，发射和接收数据 FIFO、上电复位电路和通用数字 I/O 等内置功能。

特点

IEEE 802.15.4g

无线 M-Bus

125 C° 的高温支持 (Si4468/7)

频率范围=119–1050 MHz

接收灵敏度 = -124 至 –133 dBm

调制

(G)FSK、(G)MSK、2(G)FSK、4(G)FSK

OOK

高达 +20 dBm 的最大输出功率

+27 dBm 或 +30 dBm 的 PA 支持

低活动功耗

前导码探测模式

10/13 mA RX

18 mA TX ， +10 dBm (Si4460)

超低电流断电模式

30nA 关机，40 nA 待机

数据速率 =0.1 kbps 到 1 Mbps

电源 = 1.8 - 3.8 V

出色的选择性能

58 至 69 dB 相邻频道

1 MHz 处，阻断增益 > 73 dB

针对 >8 MHz 的偏移，阻断增益 > 84 dB

天线分集和 T/R 开关控制

高度可配置的分组处理程序

低 BOM

低电量探测器

温度传感器

Si4460/61/63/64/67/68 RF ICs Layout Design Guide

1. Introduction

The purpose of this application note is to help users design PCBs for the next generation EZRadioPRO™ RF ICs,i.e. the Si4460/61/63/64/67/68 devices (henceforth referred to as EZRadioPRO™ RF ICs) using good designpractices that allow for good RF performance. The matching principles described in detail in “AN627: Si4460/61/67

Low-Power PA Matching” and in “AN648: Si4063/Si4463/64/68 TX Matching”.

The RF performance and the critical maximum peak voltage on the output pin strongly depend on the PCB layoutas well as the design of the matching networks. For optimal performance, Silicon Labs recommends the use of thePCB layout design hints described in the following sections.

2. Design Recommendations when Using Si4460/61/63/64/67/68 RF ICs

》Extensive testing has been completed using reference designs provided by Silicon Labs. It isrecommended that designers use the reference designs “as-is” since theyminimizedetuning effectscaused by parasitics or generated by poor component placement and PCB routing.

》The compact RF part of the designs is highlighted by a silkscreen frame, and it is strongly recommended touse the same framed RF layout in order to avoid any possibility of detuning effects. Figure 1 shows theframed compact RF part of the designs.

Figure 1. Compact RF Part of the Designs Highlighted on Top Silkscreen

》When layouts cannot be followed as shown by the reference designs (due to PCB size and shapelimitations), the layout design rules described in the following sections are recommended.

The Si4460/61/63/64/67/68 devices can use the following TX matching networks:

》Class E (CLE)

》Switched Current (SWC)

》Square-Wave (SQW)

The basic types of board layout configurations are as follows:

》Split TX/RX

》Direct Tie

》Switched TX/RX

》Diversity

In the Split TX/RX type, the TX and RX paths are separated, and individual SMA connectors are provided for each

path. This type of Pico Board is best suited to demonstrations of the output power and sensitivity of the

EZRadioPRO™ RF ICs.

In the Direct Tie type, the TX and RX paths are connected together directly, without any additional RF switch.

In the Switched TX/RX type, the boards contain a single antenna and a single-pole double-throw (SPDT) RF switch

to select between the TX and RX paths.

In the Diversity type, there are two antennas, both of which can be connected either to the TX or the RX path by a double-pole double-throw (DPDT) RF switch.