This technology produces a switch with less loss than conventional gaas processes. A high power solid state tr switch by gerald hiller and rick cory, skyworks solutions, inc. They are also referred to as single pole, double throw and abbreviated spdt or sp2t. Figure 5 shows a singlepole doublethrow spdt rf switch and its bias circuit. This configuration is known as single pole, single throw and is often abbreviated spst or sp1t.
Switch driver circuit this shows a the pin diode driver circuit and some of the additional circuitry. Dec 12, 2017 pacific antenna easy tr switch kit kit description the easy tr switch is an rf sensing circuit with a double pole double throw relay that can be used to automatically switch an antenna between a separate receiver and transmitter. Highspeed analog cmos technology is used to achieve low power consumption at moderate speeds. Pin diode sp4t switches from pasternack are most commonly used in rf, microwave and millimeter wave test systems for routing varying signals between instruments, allowing multiple tests to be performed at the same time using the same setup. The sky12208478lf is a high power handling, singlepole, doublethrow spdt silicon pin diode switch.
The advantage of this arrangement is the broadband characteristic. Electronic tr switching and the ameritron qsk5 building. The driver circuit may further comprise an antenna contact coupled to a node between a receive pin diode and a transmit pin diode of the plural pin diodes, a receive contact coupled to a node between the receive pin diode and a shunt pin diode of the plural pin diodes, and a transmit contact coupled to the transmit pin diode, wherein the bias. Jul 26, 2008 the carrier lifetime of pin diode i use is 10microsecondstyp.
The hf power coming from the tx will see 50 ohms towards the antenna, and 0r ohms towards the pin diode at both t points r is the resistance of the pin diode. Secondly, a section focusing on pin diode theory will be presented. I assume that it is a simple series switch with the diode in series with the rf signal path, but it could be more complex with some shunt diode or other complexities. Design and performance of a high speed driver circuit for pin. I previously published a video that introduced the topic of how diodes can be used as. The use of rf and microwave switches based on pin diodes is widely spread. This series of diodes can operate up to 6ghz with highvoltage handling capabilities and together with outstanding rf performance, they simplify designin because of their extreme low forward. At high frequencies, the diode behaves as a resistor. The 470pf dc blocking capacitor on the coaxial wire should be shielded in a metal case that connects coax ground to antenna connector ground.
Us4502025a high speed pin diode switched antenna coupler. To simplify the application all ics include the power ramping adjustable with an external capacitor. Infineon pin diodes come with low loss and low distortion levels and are suitable for a wide range of mobile communications and rf applications. The upp9401 would be an excellent choice for surface mount spdt and spst switches. The pin diodes are biased through an inductor, which is isolating the bias supply. Pulsar microwaves 2way switches are available in absorptive and reflective designs from 20 mhz to 18 ghz. Pin diode switches from fairview microwave are instock and will ship the same day. Pin diode drivers introduction the dh0035dh0035c is a ttldtl compatible, dc coupled, high speed pin diode driver.
Introduction radio transceiver designers are always faced with a dilemma. Sp2t rf pin diode switches to 18 ghz pulsar microwave. This pin diode rf switch is the ideal antenna switch for vhf and uhf and work with the pin diodes which are special high frequency switching diodes with very low internal capacitance. Note that the opamp comparator and pin diode circuit is replicated so that there are a total of four of them one for each of the antennas although there is no reason why 6 or 8 couldnt be used if an antenna array was constructed thusly.
These pin diode switches are part of over 1 million rf, microwave and millimeter wave products that is instock and will ship sameday shipment from fairview. The bias circuit typically uses a lowpass filter between the rf circuit and the switch driver. It is designed for spdt switches operating with a cw input a power up to 100 w. One disadvantage is the complexity of the biasing network that is required. Us4486722a pin diode switched impedance matching network. How to switch between two antennas with a simple and reliable device built with pin diodes. The antenna is connected to the other side of receive switch and one side of the amplifier output switch.
Pin diode wafers on film frame building on a proven legacy including products developed at alpha industries prior to its merger with conexants wireless division to become skyworks, our product portfolio includes pin, schottky, varactor and limiter diodes for a wide variety of microwave applications. This is the basis for using the pin diode in a wide variety of rf switch. Pin diodes in a diseqc switch the choke coil you see on the schematic is build by winding 4 turns of 0. Pin diodes are used as currentcontrolled resistors at rf and microwave. This is a basic tutorial on pin diodes, with some examples of how they are used in rf switch applications. Other definitions, such as the time from 1 db to 60 db levels, are occasionally employed for high isolation requirements.
Reverse voltage protection 30 mhz repetition ttl control protection test port short circuit protection operating characteristics. Initially, trying to keep things as simple as possible, i started off with the most simple version of an antenna driver, a hard switching device that selected every antenna for 14. Every pin diode in a switching circuit has an accompanying pin diode driver or. At the same time, pin diode d 1 is reversebiased, which isolates the antenna from the transmitter output. Most of the information in this chapter is based on. We have extensive experience in switch design and development for critical space, telemetry, transceiver, radar, and ew applications. I have read some ap notes of pin diodes, and got to know that switching speed of my antenna switch is not only related to carrier lifetime of pin diodes,but also related to driver. The driver utilizes fast switching npn transistors and skyworks discrete pin diodes. A diode alone is not a complete and useful switch as it is only the core switching element. Thin film metalization on ceramic substrates ensures low parasitic capacitance for fast switching, small size, and excellent reliability. High speed pin diode switched antenna coupler and method. Us patent application for programmable biasing for pin diode. Use table 3, pin diode pn series matrix to determine the pin diode pn series that best satisfies the type of pin diode selected from table 2.
Design feature antenna switching use transmitting power fets. Pin diode driver or switch driver that provides a controlled forward bias current and a reverse bias voltage. Design feature antenna switching use transmitting power. A complete electronic tr switch using pin diode switches click on any of the switches in the diagram for more information on that particular switch. This pin diode rf switch is the ideal antenna switch for vhf and uhf and work with the pin diodes which are special high frequency switching diodes with. The masw010370, made by macom technology solutions, is a fully integrated 10 w pin diode antenna switch assembled in a leadfree 3 mm 16lead pqfn plastic package. Rf pin diode sp4t switches are passive devices that route a high frequency signal through a set transmission path. How to specify pin diode switches american microwave. When using inverting input, connect bias pin 5 to noninverting input pin 6. Driver circuits for high power pin diode switches the information in this chapter is presented as a guide for the rf switch switch driver interface. External negative supply voltages may be as high as 18 volts. Thin film metalization on ceramic substrates ensures low parasitic capacitance for.
Pin diode antenna transmit receive switches transmit receive antenna switches are commonly used to connect the transceivers antenna to either the transmitter port or the receiver port. Pin diode drive circuits optimized for fast switching. Even more switching devices may be required for higher power handling or improved switch isolation. Use table 2, relative pin diode performance evaluation matrix to determine the type of pin diode that best satisfies the switch design selected from table 1. In this chapter theory surrounding pin diode switches and their use in rf and microwave applications will be presented. Us patent application for programmable biasing for pin. Physically, this circuit is a single pole double throw switch spdt that. This driver is designed to provide forward currents up to 100 ma for each diode, and 28 v reverse bias. The internal resistance of a pin diode can be remotely variated from 1 to 10. Pin diode drivers api technologies offers a complete lineup of pin diode switch drivers with output current capability of 10 ma to 50 ma and switching speeds as fast as 6 ns.
It might be helpful if you post a minischematic of the components in the area of the pin switch. The transceiver is connected to one side of the receive switch and the amplifier input switch. A high speed circuit was fabricated and tested to drive each pin diode switch. This will be followed by a section concerning the pin diode driver. A pin diode has two switching speeds from forward bias. The switch features enhanced algaas anodes which are formed using macoms patented heterojunction technology. Pulsar microwave manufactures pin diode rf switches that are controlled by ttl logic. Pin diode driver circuits are a pain to design and build. Fourposition hf antenna switch with pc control nuts. It is capable of delivering peak currents in excess of one ampere at speeds up to 10 mhz. Part number is um4010,manufactured by microsemi corp. Inputs are compatible with standard logic families. A universal pin diode driver with excellent noise immunity, very fast switching, 100 ma current spikes and available test points for increasing quiescent output current.
Low output resistances allow it to develop high output current spikes to ensure fast switching speeds. There are some great vendors out there that can supply you with many. They have been engineered to function in 50ohm systems, and are designed to operate from 40 mhz to 18 ghz. The two quarter wave sections operate in identical fashion in tx mode. Yet another pin diode antenna switch is shown in figure 3. Our silicon heterolithic microwave integrated circuit hmic pin diode process is ideal for high power and broadband switches operating from 50 mhz to 26 ghz. References 1,2 provide a fuller treatment of this subject and can be used as a basis for rf switch switch driver interface designs. How and why to use pin diodes for rf switching digikey. Pin, gaas and gan switch high speed required frequency range ghz. Soft vs hard antenna commutation rdf radio direction finding. Diode drivers 17a, 17b, 17c, 17d, and 17e drive the appropriate pin diodes 71, 73, 75, 77, and 79 respectively. At a minimum, an rf switch based on pin diodes needs a dc blocking capacitor to prevent the dc bias current from reaching the rf output, and an rf choke to provide a path for the dc bias current to return while blocking the rf signal. L3 nardamiteq designs and manufactures a broad line of digital pin diode switches covering multioctave bands from 80 mhz to 44 ghz.
The carrier lifetime of pin diode i use is 10microsecondstyp. Nov 18, 2016 the driver circuit may further comprise an antenna contact coupled to a node between a receive pin diode and a transmit pin diode of the plural pin diodes, a receive contact coupled to a node between the receive pin diode and a shunt pin diode of the plural pin diodes, and a transmit contact coupled to the transmit pin diode, wherein the bias. Macoms madr007097000100 is a spdt driver used to interface between ttl logic signals and pin diode based microwave switches. The antenna driver of the doppler rdf is a very important part of the total system, and therefore it may need some extra explaining. High throw count 4t switches antenna switch modules asm. At a minimum, an rf switch based on pin diodes needs a dc blocking capacitor to prevent the dc bias current from reaching the rf output, and an rf choke to provide a path for the dc bias current to. Pin diode switched impedance matching network having diode. Switching speed of a pin diode switch is generally defined as the time for the rf to traverse 10% to 90% levels. The pin diode in a switching circuit requires an accompanying pin diode driver or switch driver that provides a controlled forward bias current and a reverse bias voltage. Nov 08, 20 this is a basic tutorial on pin diodes, with some examples of how they are used in rf switch applications. The driver provides 3 pairs of complementary outputs that drive the bias ports in the sp3t pin diode switch. In this configuration, rf is sampled by the processor, the frequency is sent to the pc and mapped to your selected antenna, and the change antenna command is set to the switch. A pin diode is a diode with a wide, undoped intrinsic semiconductor region between a ptype semiconductor and an ntype semiconductor region. The increase in speed over the former driver system is a factor of 5.
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