Emc Technology, Inc.

Smiths Interconnect Microwave Components, Inc.

Smith Interconnect Microwave Components, Inc.

Altera Corporation

Robert J Blacka

Joseph B Mazzochette

David Markman

Nelson Roldan

Francis J Verderame

Alen Fejzuli

Paul Davidsson

Kai Loh

Gene A Perschnick

David A Raymond

A surface mount chip resistor for increasing power handling capabilities of radio frequency (RF) circuits and for minimizing parasitic capacitance and inductance effects, the chip resistor includes a ceramic substrate having a main portion and an outrigger. A resistor element is between an input contact and an output contact on a top surface of the main portion. A ground plane attachment area is on a top surface of the outrigger. The ground plane attachment area is mounted to a ground plane of a circuit board to provide a heat pathway for dissipating heat generated by the resistor element.

Chip resistor with outrigger heat sink

The present invention is a wideband temperature-dependent attenuator. In a preferred embodiment the attenuator is a modified Tee attenuator having first and second resistors connected in series at a first node and third and fourth resistors connected in shunt between the first node and ground. In a physical implementation of the attenuator, the third and fourth resistors are on opposite sides of the first and second resistors. Preferably, each of the four resistors is formed as a thick film resistor.

Wideband temperature-variable attenuator

A preferred embodiment of the present invention comprises at least first and second thermistors, arranged into a classical Tee, Pi, or Bridged Tee attenuator design, a heating element, a temperature sensor, and a control circuit. The thermistors have different temperature coefficients of resistance and are in close proximity to the heating element and the temperature sensor. The control circuit receives a voltage signal from the temperature sensor, compares that signal with a voltage signal specifying a desired temperature, and applies electrical energy to the heating element until receiving a signal from the temperature sensor that the temperature of the thermistors matches the desired temperature. As a result, the attenuation of the attenuator can be changed at a controlled rate by varying the temperature of the thermistors, while the impedance of the attenuator remains within acceptable levels.

Voltage controlled attenuator with no intermodulation distortion

A temperature and frequency variable gain attenuator comprises a temperature variable attenuator and a temperature variable filter network whose resistances changed to c generate different responses that vary over temperature and frequency. At least three different thick film thermistors are used, with two of these used on the attenuator and a third one used on the filter network. The temperature coefficients of the thermistors are different and are selected so that the attenuator and filter network attenuation change at a controlled rate with changes in temperature while the impedance of the gain equalizer remains within acceptable levels. Substantially any temperature coefficient of resistance can be created for each resistor by properly selecting and mixing different inks when forming the thick film thermistors. Furthermore, the attenuator can have either a negative temperature coefficient of attenuation or a positive temperature coefficient of attenuation.

Temperature and frequency variable gain attenuator

The present invention is an absorptive-type cable temperature and frequency equalizer that offsets changes in the gain of the other circuit components cables with increases in temperature and/or frequency. The equalizer comprises a temperature variable filter network having component values and a temperature coefficient of resistance that vary over temperature and frequency to produce a desired response. The temperature and frequency equalizer has at least one thick film thermistor connected in series with a quarter wavelength transmission line. The thermistor absorbs forward and reflected signals at lower frequencies.

Temperature and frequency equalizer

An absorptive temperature-variable microwave attenuator is produced using a first plurality of shunt resistors separated by quarter-wave transmission lines connected by a series resistor with a second plurality of shunt resistors separated by quarter-wave transmission lines. At least one or more of the resistors are temperature-variable resistors. The temperature coefficients of the temperature-variable resistors are selected so that the attenuator changes at a controlled rate with changes in temperature while attenuator remains relatively matched to the transmission line. In one embodiment, the resistors are thick-film resistors and a variety of temperature coefficients can be created for each resistor by properly selecting and mixing different inks when forming the thick film resistors. Furthermore, attenuators can be created having either a negative temperature coefficient of attenuation or a positive temperature coefficient of attenuation.

An absorptive temperature-variable microwave attenuator is produced using at least two temperature-variable (or fixed) resistors in series with a transmission line. The temperature coefficients of the temperature-variable resistors are selected so that the attenuator changes at a controlled rate with changes in temperature while attenuator remains relatively matched to the transmission line. In one embodiment, the resistors are thick-film resistors and a variety of temperature coefficients can be created for each resistor by properly selecting and mixing different inks when forming the resistors. Furthermore, attenuators can be created having either a negative temperature coefficient of attenuation or a positive temperature coefficient of attenuation.

High-frequency temperature-variable attenuator

A power sensing RF termination comprising a calibration means allows the user to correct for part-to-part variation, miss match loss and output offset. The power sensing RF termination comprises a first and second temperature sensitive resistors connected at a first common junction, a switching means for connecting either an RF input or a DC power reference to the first common junction, a first switch for connecting either a DC voltage source or a first current detecting resistor to the first temperature sensitive resistor, and a second current detecting resistor connected to the second temperature sensitive resistor. A first output terminal is connected to the junction between the first switch and the first temperature sensitive resistor. A second output terminal is connected to the first common junction. A third output terminal is connected to the junction between the second temperature sensitive resistor and the second current detecting resistor. The first and second temperature sensitive resistors have substantially the same temperature coefficient of resistance; but the first temperature sensitive resistor has a positive temperature coefficient of resistance while the second temperature sensitive resistor has a negative temperature coefficient of resistance. Using the measurements of the voltages at the first, second and third output terminals, a calibration table is formed correlating the power absorbed in the first and second temperature sensitive resistors to the ratio between the voltage drop across either the first or second temperature sensitive resistor and the voltage drop across both the first and second temperature resistive resistors.

Power sensing RF termination apparatus including temperature compensation means

A circuit for determining power changes in an RF circuit includes first and second temperature sensitive resistors connected in parallel with an RF input terminal so as to have a common junction therewith. The first resistor has a positive temperature coefficient of resistance and the second resistor has a negative temperature coefficient of resistance. A DC input terminal is connected to one of the temperature sensitive resistors and an output terminal is connected to the common junction of the two temperature sensitive resistors. Third and fourth temperature sensitive resistors have a common junction. The third resistor has a positive temperature coefficient of resistance and the fourth resistor has a negative temperature coefficient of resistance. The DC input terminal is also connected to one of the third and fourth temperature sensitive resistors, and an output terminal is connected to the common junction of the third and fourth temperature sensitive resistors. To improve the linearity of the circuit at high powers, each of the individual temperature sensitive resistors can be replaced with a pair of temperature sensitive resistors, one having a positive temperature coefficient of resistance and the other having a negative temperature coefficient of resistance. In such circuit four output terminals are provided with each output terminal being connected to the junction between the temperature sensitive resistors of each pair.

Termination for RF circuit which senses changes in power and which is

A temperature compensating voltage variable attenuator includes at least two temperature variable resistors. The temperature variable resistors have different temperature coefficients of resistance, preferably, with one temperature variable resistor having a positive temperature coefficient of resistance and the other temperature variable resistor having a negative temperature coefficient of resistance. The temperature coefficient of resistance of the temperature variable resistors being such that the attenuation of the attenuator varies with changes in temperature of the attenuator. A voltage variable heater resistor is adjacent both temperature variable resistors so that a change in the voltage applied to the heater resistor changes the temperature of the heater resistor. The heat from the heater resistor is applied to the temperature variable resistors so as to change the resistance of the temperature variable resistors. This provides a controlled change in the attenuation of the attenuator.

Heated temperature variable attenuator

A high accuracy programmable attenuator for accurately selecting and maintaining desired values of attenuation for a high frequency RF signal. The attenuator is comprised of a plurality of cells wherein each cell is comprised of an individual attenuator, a switch and a bias resistor. Each bias resistor is comprised of a plurality of individual resistors arranged in a binary sequence and wire bonds are used to short out undesired resistors for compensating for insertion loss and obtaining desired attenuation. The attenuators of the circuit are also arranged in a binary sequence so as to allow the user to select from a large variety of attenuations in small increments.

Ultrahigh accuracy digital programmable attenuator

A method is provided for soldering using tin-containing solder to substrate surfaces that are gold plated wherein a selected portion of the gold plated surface is treated by impacting with a high velocity stream of fine nickel containing abrasive particles to remove all the gold from the treated surface and then effecting joining to the treated surface by conventional soldering techniques.

Growing community of inventors

Pennsauken, NJ, United States of America

Robert J Blacka