AARTS Smart Fixture

Accel-RF offers a wide variety of standard and custom fixture designs.  Our innovative fixture designs incorporate many years of expertise to yield robust solutions to high-temperature testing. 

RF Fixtures

All of the RF fixtures support a single Device Under Test (DUT) and incorporate a heater core that is unique to that channel.  Hence, it is possible to dynamically adjust the DUT surface temperature as time elapses to account for variations in power dissipation and thus maintain a constant channel (or junction) temperature.  This is a unique feature that systems employing a common heat source (thermal plate or oven) are not capable of supporting.  In those cases, the DC input power and RF output power must be held constant in order for the device channel temperature to be consistent with the rest of the population of devices.  Yet, variations in drain current and output power are key parameters of interest in the reliability prediction.  The Accel-RF paradigm offers maximum flexibility to support both modes of operation.

Standard RF Fixture:

The standard RF fixture supports both pulsed and non-pulsed operation.  It employs SMA input/output connections.  For RF output powers over 10W, an N-type connector may be used to replaces the SMA connector because of its power-handling capability.  The golded-plated brass block, located in the center area houses the heater core.  The outer part of the fixture is designed to stay relatively cool.  With the hot area at 250°C, the outer area will be less than ~80°C.   An air gap separates the hot from cool area, with a coplanar waveguide transition across the air-gap discontinuity.

The pulse circuitry supports pulse widths down to 10us, with periods from 30us to 1ms.  Synchronized pulsing of the Bias1, Bias2, and RF signals is fully programmable via the LifeTest software.  An additional capability, that is sometimes desirable in the MEMS market, is the ability to define and create de-bounce "kick" pulses at the beginning and end of the pulse cycle.  These may be as short as 1us at full 100-V pulsed operation.

Millimeter-Wave Fixture:

The Millimeter-Wave fixture is designed for operation at very high-frequencies.  A variety of models cover 20GHz to 94GHz.  Waveguide input is converted to a planar (microstrip) waveguide inner area.  This allows mounting of mmW MMICs or planar devices, while allowing lower loss transmission line routing of the mmW power.  This fixture also supports both pulsed and non-pulsed operation.

Multi-Function Fixture:

The Multi-Function fixture offers the ability to route mulitple RF and DC channels into one device.  Hence, MMICs and other module-like devices that require more than just two power supplies may be tested.  The fixture shown here also routes two sets of RF inputs and outputs to the device.  When married with the proper RF Control Unit (RFU) configuration, mult-band devices may be stimulated.  Further, the pulsed controls may be used to force cycling between bands to test switching performance.

DC-Only Fixtures

As the name implies, "DC-only" systems are limited to supplying only DC and thermal stimulus to the device.  There are no RF signals available.  Further, in order to maximize channel density the DC-only version of the AARTS system employ fixed heater blocks, mounted in the oven floor and not the fixture itself, which are shared amoung several channels.  Typically, three devices share a heater block; however, in the dual-device fixture up to six channels may share the heater.

Since multiple channels share a common heater, they must be operated in a constant power dissipation mode (i.e. active bias) in order to maintain consistent channel (or junction) temperatures between devices (a limitation that many legacy in-house systems suffer).  However, the option does exist to operate the system in constant channel-temperature control mode (similar to that of the RF fixtures), but only one device may be the controlling element.    Two DC-only fixture options are available:

RF-Ready DC Fixture:

The RF-Ready DC fixture provides space for mounting RF input and output matching circuits.  Hence, it is possible to tune up the assembly at a remote test station, such as a network analyzer, to peak performance and then run the life test with DC stimulus.  The matching structures also allow incorporation of more complex stabilization structures.

Dual-Device DC Fixture:

The dual-device DC fixtures work with systems that provide DC and thermal stimulus only to the device.  There are no RF signals available.  This option provides the most channel density of any fixture.  As with the RF-Ready DC fixture, it does not contain an on-board heater, but shares a common heater block with neighboring channel.  The device mounts in a PGA-style package and does not provide room for external bias or stabilization components.  Therefore, it is important to know that the devices are inherently stable without those elements near the device.