WO2005109566A1 - Compact balun for rejecting common mode electromagnetic fields - Google Patents
Compact balun for rejecting common mode electromagnetic fields Download PDFInfo
- Publication number
- WO2005109566A1 WO2005109566A1 PCT/US2004/010749 US2004010749W WO2005109566A1 WO 2005109566 A1 WO2005109566 A1 WO 2005109566A1 US 2004010749 W US2004010749 W US 2004010749W WO 2005109566 A1 WO2005109566 A1 WO 2005109566A1
- Authority
- WO
- WIPO (PCT)
- Prior art keywords
- balun
- slotline
- waveguide
- transition
- microstrip
- Prior art date
Links
Classifications
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01P—WAVEGUIDES; RESONATORS, LINES, OR OTHER DEVICES OF THE WAVEGUIDE TYPE
- H01P5/00—Coupling devices of the waveguide type
- H01P5/08—Coupling devices of the waveguide type for linking dissimilar lines or devices
- H01P5/10—Coupling devices of the waveguide type for linking dissimilar lines or devices for coupling balanced with unbalanced lines or devices
Definitions
- This invention relates to waveguides. Specifically, the present invention relates to baluns for canceling common mode electromagnetic energy in differential input signals or for providing differential output signals lacking common mode energy in response to an input signal.
- balun converts unbalanced transmission line inputs into one or more balanced transmission line outputs or visa versa.
- Baluns are employed in various demanding applications including output stages of delta sigma modulator Direct Digital Synthesizers ( ⁇ DDS) and antenna feeds.
- ⁇ DDS Direct Digital Synthesizer
- Such applications demand miniature, wide-bandwidth (wideband) baluns compatible with integrated circuits and capable of rejecting common mode energy from differential inputs or providing differential outputs lacking common mode energy.
- ⁇ DDS's are often employed to generate analog output signals with desired amplitudes, frequencies, and phases based on certain digital inputs.
- ⁇ DDS's are employed in various applications, including active pulse radar and digital wireless communications, to facilitate signal waveform generation for signal mixing, up-converting, down-converting, frequency synthesis, and signal offsets.
- a conventional ⁇ DDS employs a 1-bit Digital-to- Analog Converter (DAC) to selectively sample an analog input signal to produce a corresponding digital output signal.
- the DAC must have a relatively high sampling rate to compensate for the low 1-bit resolution quantizer. Consequently, the output of the 1-bit DAC is often a high- frequency pulse-like signal. This 1-bit DAC output is typically filtered to remove quantization noise.
- 1-bit DACs employed in ⁇ DDS's often provide dual pulse-like output signals, which are 180 degrees out of phase. These differential pulse-like signals may occur over a wide frequency range and must be converted to a single output via a balun.
- the 1-bit DAC includes transistors, which often have slightly different rise and fall times. Differences in transistor rise and fall times create undesirable common mode components in pulsed output signals. For optimum DDS performance, these common mode components must be rejected in the final ⁇ DDS output.
- wire-wound ferrite baluns are employed to convert differential input lines into a single balanced output transmission line. These baluns have iron cores wrapped in wire and act as power transformers.
- baluns are bandlimited at lower frequencies, typically cutting off frequencies beyond two or three gigahertz, which is undesirably low for many ⁇ DDS applications.
- ferrite baluns are more suitable for continuous wave applications and less suitable for pulse applications, as ferrite baluns are often susceptible to reflections resulting from fast input pulses.
- the baluns are made larger.
- the large ferrite baluns are difficult to incorporate into miniature ⁇ DDS integrated circuits and poorly reject common mode energy.
- baluns are constructed using various waveguides having quarter wavelength sections. Unfortunately, use of quarter wavelength sections may result in undesirably large baluns.
- these baluns are relatively narrow-banded and are susceptible to large reflections when fed with pulsed inputs.
- Such a balun can also provide balanced differential outputs lacking common mode energy from a balanced input.
- an efficient ⁇ DDS that incorporates the efficient wideband balun.
- the inventive balun is adapted for use with Direct Digital Synthesizer (DDS) applications.
- the balun includes a first mechanism for receiving an input signal having an undesirable common mode component.
- a second mechanism rejects the undesirable common mode component via a waveguide transition.
- the first mechanism includes an input microstrip waveguide.
- the waveguide transition is a single microstrip-to-slotline transition.
- the single microstrip-to-slotline transition includes the input microstrip waveguide positioned to cross over a slotline in a ground plane of the microstrip.
- the slotline is terminated at a first end via a wedge in the ground plane. A second end of the slotline provides an output of the balun.
- the input signal includes a first input signal and a second input signal, which are input at opposite ends of the input microstrip waveguide.
- the first input signal and the second input signal have a desired differential mode component and an undesired common mode component.
- the first mechanism includes two microstrip waveguides.
- the input signal includes a first input signal travelling on a first microstrip waveguide and a second input signal travelling on a second microstrip waveguide.
- the desired signal components of the first and second signal are approximately 180 degrees out of phase.
- the waveguide transition includes a transition from the first and second microstrip waveguides to a single slotline output waveguide.
- the slotline output waveguide rejects common mode energy and passes differential mode energy corresponding to the desired signal components.
- the transition further includes a first transition from the first microstrip line to a first slotline section and a second transition from the second microstrip line and a second slotline section.
- the transition also includes a coplanar waveguide section fed via the first slotline section and the second slotline section and a transition from the coplanar waveguide section to an third slotline section corresponding to the slotline output waveguide.
- the first, second, and third slotline sections and the coplanar waveguide section are implemented in a ground plane associated with the first and second microstrip waveguides.
- the first mechanism includes first and second coaxial waveguides.
- the waveguide transition includes a dual coax-to- coplanar waveguide-to-single coax transition.
- a resistor network or bridge in the waveguide transition facilitates load matching and attenuates back-reflected common mode energy.
- the novel design of the present invention is facilitated by use of an efficient waveguide transition to reject undesirable components from an input signal.
- Fig. 1 is a diagram of a ⁇ DDS employing a unique broadband balun and constructed in accordance with the teachings of the present invention.
- Fig. 2 is a more detailed perspective view of the balun of Fig. 1.
- Fig. 3 is a more detailed perspective view of a first alternative embodiment of the balun of Fig. 2.
- Fig. 4 is a more detailed diagram of a second alternative embodiment of the balun of Fig. 2.
- Fig. 1 is a diagram of a ⁇ DDS 10 employing a compact broadband balun 20 that is constructed in accordance with the teachings of the present invention.
- various well-known components such as power supplies, clocking circuitry, software feedback loops, and so on, have been omitted from the figures.
- those skilled in the art with access to the present teachings will know which components to implement and how to implement them to meet the needs of a given application.
- the ⁇ DDS 10 includes, from left to right, a Random Access Memory (RAM) 12, a Multiplexer (MUX) 14, a 1-bit Digital-to-Analog Converter (DAC) 16, an attenuator 18, and the broadband balun 20 and an optional set of wideband filters 22 that is connected at the output of the balun 20.
- the various components 12-22 are connected in series.
- the ⁇ DDS 10 is a feed-forward system. In operation, the ⁇ DDS 10 outputs a desired waveform based on data stored in the RAM 12.
- ⁇ DDS 10 may be used for various applications including waveform generation for fine frequency synthesis or for offset frequency generation.
- Parameters specifying desired waveform characteristics are written to the RAM via a computer or other processor (not shown).
- the RAM incorporates a Field-Programmable Gate Array (FPGA) bus exchange switch for facilitating timing and control.
- FPGA Field-Programmable Gate Array
- Digital waveform data is selectively input to the MUX 14 from the RAM 12 in response to control signaling from a computer or processor (not shown).
- the output of the RAM 12 is often a bus, such as a 32-bit bus.
- Each output bit is converted to a differential signal pair at the input of the MUX 14 via methods known in the art.
- the MUX 14 then provides a differential output signal on two conductors.
- the differential output signal represents a stream of single bits.
- the 1-bit differential output signal from the MUX 14 is input to the 1-bit DAC • 16.
- the 1-bit DAC 16 employs a 1-bit quantizer and a high sampling rate to compensate for the low resolution of the 1-bit quantizer.
- the output of the 1-bit DAC 16 will be a high-frequency, multi-GHz, pulsed signal that has excess quantization noise as represented by the spectrum 24.
- naturally occurring differences in rise and fall times of various transistors in the 1-bit DAC 16 and MUX 14 cause an undesirable common mode component in the differential outputs of the 1-bit DAC 16.
- the outputs of the 1-bit DAC 16 are often provided via microstrip transmission lines, dual slotlines, a coplanar waveguide, or coaxial cables.
- signals on the differential output microstrip lines are exactly 180° out of phase.
- an undesirable common mode component exists.
- the balun 20 removes this undesirable common mode component and provides a single output based on the differential inputs.
- the common mode component is often called the even mode component.
- the desired differential mode component is often called the odd mode component.
- a balun is a device that converts a balanced signal to an unbalanced signal or visa versa. Dual-conductor transmission lines are inherently balanced, while three-conductor transmission lines are potentially unbalanced.
- the balun 20 employs a unique transition from unbalanced microstrip transmission line (3 conductors) to a balanced transmission line (two conductors) to reject the undesirable common mode component from the output of the 1-bit DAC 16. Any common mode energy that is not dissipated via the balun 20, and is reflected back, is absorbed via the optional attenuator 18.
- the attenuator 18 may be implemented as a pi ( ⁇ ) attenuator.
- the output of the balun 20 is then provided to a filter 22, which facilitate removal of noise, such as quantization noise, from the output of the balun 20.
- the output of the filter 22 represents the desired spectrum 26, which is similar to the spectrum 24 but with undesirable signal components and noise removed via the balun 20 and the filter 22.
- the balun 20 and filter 22 may be replaced by a suitable active filter. However, active filters may introduce prohibitive distortion and phase noise for some applications.
- the input to the balun 20 may be back-terminated so that energy reflected from the balun transition dissipates in the resistors of the back termination. In this case, the attenuator 18 may be omitted.
- the balun 20 may incorporate a load matching resistor network to dissipate reflected energy, as discussed more fully below.
- Use of differential signals in the MUX 14 and 1-bit DAC 16 may reduce phase noise and pulse distortion, and may improve settling time and the Signal-to-Noise Ratio (SNR) of the ⁇ DDS 10.
- SNR Signal-to-Noise Ratio
- Use of the balun 20 to reject common mode energy increases the SNR of the ⁇ DDS 10.
- Conventional baluns are often too large to be efficiently integrated in the ⁇
- balun 20 of the present invention is suitable for chip-level integration is readily implemented in GaAs and other integrated circuit chip environments.
- This feed-forward ⁇ DDS 10 eliminates stability issues associated with conventional ⁇ DDS hardware and feedback loops.
- ⁇ modulator feedback loops (not shown) employed by the ⁇ DDS 10 reside in the software (not shown) running on the computer that generates the waveform parameters that are input to the RAM 12. The computer can simulate high-order ⁇ modulators while maintaining loop stability.
- Fig. 2 is a more detailed perspective view of the balun 20 of Fig. 1.
- the balun 20 includes a slotline waveguide 32 formed between a first groundplane section 34 and a second groundplane section 36.
- the slotline waveguide 32 includes an open end 38 and an output end 42.
- the open end 38 opens into a N-shaped cut-away or wedge in the groundplane sections 34 and 36, which is formed by angled groundplane edges 40.
- a microstrip waveguide 44 passes perpendicularly to the slotline 32 over the ground plane sections 34 and 36.
- the microstrip 44 includes a first microstrip section 46, which is supported by the first ground plane section 34, and a second microstrip section 48, which is supported by the second groundplane section 36.
- the dielectric between the microstrip 44 and the ground plane sections 34, 36 is not shown.
- Various high-dielectric constant materials, such as alumina, may be employed. Those skilled in the art will know which dielectric material to use to meet the needs of a given application.
- the ground planes sections 34 and 36 and the microstrip 44 are implemented via copper or gold conductors. The dimensions of the ground planes sections 34 and 36 and the microstrip 44 are application-specific and may be determined by one skilled in the art with access to the present teachings to meet the needs of a given application.
- the microstrip 50 passes over the slotline 32 at a microstrip-to-slotline transition 50.
- the different microstrip sections 46 and 48 may be considered as different microstrip lines that are separated by the microstrip-to-slotline transition 50.
- the ends of the microstrip 44 are fed with differential input signals 52 and 54 at opposite ends 46 and 48, respectively.
- Exemplary electric field lines associated with the differential input signals 52 and 54 are shown.
- the differential input signals 52 and 54 which are also called anti-phase signals, are approximately 180 degrees out of phase. Any common mode components, such as components that are in-phase, are rejected at the microstrip-to-slotline transition 50. Any energy that is reflected back from the transition 50 is attenuated in the attenuator 18 of Fig. 1.
- the balun 20 introduces 90-degrees of phase rotation in each slotline leg 46 and 48 to facilitate canceling common mode energy components and passing differential mode electromagnetic energy components. Baluns that employ quarter wavelength sections or employ 180-degrees of rotation in different balun legs are often large and not physically symmetric, which can lead to poor performance. Baluns 20 and 20' of the present invention are physically symmetric.
- the desired odd mode or differential mode component 56 is coupled to the slotline 32, which is a balanced transmission line.
- the differential mode component 56 that remains on the balanced slotline 32 is necessarily balanced due to the balanced nature of the slotline 32 and lacks undesirable common mode energy components.
- balun 20 Although the design of the balun 20 appears structurally simple, it has significant advantages when used as a balun.
- the balun 20 exhibits broadband performance from mulit-megaHertz to multi-gigaHertz frequencies and efficiently accommodates pulsed waveforms.
- the balun 20 is readily miniaturized and incorporated into integrated circuits. Unlike many conventional baluns, which may rely on quarter wavelength sections, the performance of the balun 20 is less size- dependent. Excellent broadband performance may be achieved with a miniature balun constructed in accordance with the teachings of the present invention.
- balun 20 of the present invention is not limited to DDS applications.
- the present invention may be adapted to any application requiring a compact wideband balun that rejects common mode energy from differential input signals.
- the balun 20 may be fed in reverse, providing differential output signals lacking common mode energy from a signal input at the slotline end 42.
- the balun 20 may be employed to convert one input signal into a differential output signal pair.
- Such a balun for example, may be employed to convert the balun' s slotline output back into a differential signal for a fully differential implementation of the filter 22 of Fig. 1.
- balun 20 may be adapted to the balun 20 without departing from the scope of the present invention.
- Various conventional techniques and features not disclosed may also be employed to further lower the cutoff frequency of the balun 20, which is already low enough for DDS synthesized bandwidth in the delta-sigma DDS application 10 of Fig. 1.
- Fig. 3 is a more detailed perspective view of a first alternative embodiment 20' of the balun 20 of Fig. 2.
- the alternative balun 20' includes a groundplane 62 having a first groundplane section 64, a second groundplane section 66, and a third groundplane section 68.
- the groundplane sections 64, 66, and 68 are positioned to form a first slotline section 70 between the first groundplane section 64 and the second groundplane section 66.
- a second slotline section 72 is formed between the first groundplane section 64 and the third groundplane section 68.
- a third slotline section 74 is formed between the second groundplane section 66 and the third groundplane section 68.
- a coplanar waveguide section 76 interfaces the first slotline section 70 and the second slotline section 72 with the third slotline section 74 and is positioned between the three groundplane sections 64, 66, and 68.
- a coplanar waveguide-to-slotline transition 78 exists at one end of the coplanar waveguide section 76 and acts as a transition between the coplanar waveguide 76 and the third slotline section 74.
- Different legs of the coplanar waveguide section 76 originate from the different slotline sections 70 and 72.
- the coplanar waveguide section 76 may be omitted, leaving only a slotlme T-junction, without departing from the scope of the present invention.
- a first microstrip waveguide 80 passes over the first slotline section 70 approximately perpendicular to the first slotline section 70 and is terminated via a first electrical connection 84 to the second groundplane section 66.
- a second microstrip waveguide 82 passes over the first slotline section 70 approximately perpendicular to the first slotline section 70 and is terminated via a second electrical connection 86 to the third groundplane section 68.
- differential input signals 52 and 54 which are 180-degrees out of phase, are input via the first microstrip section 80 and the second microstrip section 82, respectively.
- the differential input signals 52 and 54 couple to the corresponding slotline sections 70 and 72, respectively, at transitions between the microstrips 80 and 82 and the slotline sections 70 and 72, respectively.
- Approximations to electric field lines associated with the first input signal 52 and the second input signal 54 are shown in the various sections 70-78 of the balun 20'. Opposite ends of the slotlme sections 70 and 72 are open-ended so that electromagnetic energy 52 and 54 fed to the slotline sections 70 and 72, respectively, flows toward the coplanar waveguide section 76; through the coplanar waveguide-to- slotline transition 78; and then through the third slotline section 74.
- balun 20' may be operated in reverse, such that electromagnetic energy is input to the third slotline section 74, yielding two differential output signals along the microstrip sections 80 and 82.
- Fig. 4 is a more detailed diagram of a second alternative embodiment 20" of the balun 20 of Fig. 2.
- the balun 20" includes, from left to right, a set of input DC- blocking capacitors 92, first and second input coaxial cables 94 and 96, respectively, for accommodating differential input signals, a waveguide transition section 98, and a single output coaxial cable 120.
- the waveguide transition section 98 includes a load-matching resistor bridge
- the resistor network i.e., resistor bridge 100 includes two input resistors 102, each positioned between outer conductors 110 and center conductors 112 of the input coaxial cables 94 and 96.
- Output resistors 104 are connected between the inner conductor 118 and the outer conductor 122 of the output coaxial cable 120.
- Four center resistors 106 are connected between terminals of the input resistors 102 and the output resistors 104.
- the waveguide transition section 98 is configured so that a coplanar waveguide section is formed from a first slotline 114 and a second slotline 116.
- the first slotline 114 is formed between the outer conductor 122 and the center conductor 118 of the output coaxial cable 122 and between the outer conductor 110 and inner conductor 112 of the first input coaxial cable 94.
- the second slotline 116 is formed between the between the outer conductor 122 and the inner conductor 118 of the of the output coaxial cable between the outer conductor 110 and inner conductor 112 of the second input coaxial cable 96.
- the waveguide transition section 98 may be considered a dual coax-to-coplanar waveguide-to-single coax transition.
- differential input signals 52 and 54 are input to the first input coaxial cable 94 and the second coaxial cable 96, respectively, via the optional DC blocking capacitors 92, which remove Direct Current (DC) offsets from the input signals 52 and 54.
- the differential signals 52 and 54 then pass to the waveguide transition section 98, which employs the resistor bridge 100 to facilitate load matching and maximum power transfer through the balun 98.
- Common mode electromagnetic energy is rejected at the transition between the slotlines 114 and 116 and the output coaxial cable 120. Since the output coaxial cable is a dual conductor transmission line, it does not support common mode energy. Consequently, the output signal 56 lacks the undesired even mode component that may exist in the differential input signals 52 and 54.
- the resistor bridge 100 also helps to absorb any reflected common mode energy.
- balun 20 has been constructed and tested for a particular application by the inventor and has shown to exhibit effective broadband frequency performance.
- the baluns 20, 20', and 20" of the present invention are compact, broadband baluns that exhibit a frequency-independent anti-phase response. They are suitable for use in various applications, including DDS applications, power dividers, broadband amplitude trackers, and so on.
Abstract
Description
Claims
Priority Applications (5)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP2007507285A JP4445010B2 (en) | 2004-04-07 | 2004-04-07 | Compact balun to eliminate common mode electromagnetic fields |
EP20100181791 EP2273605A3 (en) | 2004-04-07 | 2004-04-07 | Compact balun for rejecting common mode electromagnetic fields |
EP04821964A EP1735870A1 (en) | 2004-04-07 | 2004-04-07 | Compact balun for rejecting common mode electromagnetic fields |
PCT/US2004/010749 WO2005109566A1 (en) | 2004-04-07 | 2004-04-07 | Compact balun for rejecting common mode electromagnetic fields |
NO20065111A NO20065111L (en) | 2004-04-07 | 2006-11-06 | Compact balloon for suppressing common signal-based electromagnetic fields |
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
PCT/US2004/010749 WO2005109566A1 (en) | 2004-04-07 | 2004-04-07 | Compact balun for rejecting common mode electromagnetic fields |
Publications (1)
Publication Number | Publication Date |
---|---|
WO2005109566A1 true WO2005109566A1 (en) | 2005-11-17 |
Family
ID=34957741
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
PCT/US2004/010749 WO2005109566A1 (en) | 2004-04-07 | 2004-04-07 | Compact balun for rejecting common mode electromagnetic fields |
Country Status (4)
Country | Link |
---|---|
EP (2) | EP2273605A3 (en) |
JP (1) | JP4445010B2 (en) |
NO (1) | NO20065111L (en) |
WO (1) | WO2005109566A1 (en) |
Families Citing this family (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
FR2904481A1 (en) * | 2006-07-31 | 2008-02-01 | Thomson Licensing Sas | Slot type antenna e.g. vivaldi type antenna, for e.g. set top box, has feeder electromagnetically coupled to slot according to knorr type coupling, and power combination circuit directly coupled to excitation point of antenna |
RU2494501C1 (en) * | 2012-01-10 | 2013-09-27 | Федеральное государственное унитарное предприятие "Ростовский-на-Дону научно-исследовательский институт радиосвязи" (ФГУП "РНИИРС") | Out-of-limit waveguide load |
Citations (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JPS6075101A (en) * | 1983-09-30 | 1985-04-27 | Sony Corp | Balun for microwave |
US4739519A (en) * | 1985-10-31 | 1988-04-19 | Narda Western Operations | Coplanar microwave balun, multiplexer and mixer assemblies |
US5379006A (en) * | 1993-06-11 | 1995-01-03 | The United States Of America As Represented By The Secretary Of The Army | Wideband (DC to GHz) balun |
Family Cites Families (4)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US3784933A (en) * | 1971-05-03 | 1974-01-08 | Textron Inc | Broadband balun |
US3995239A (en) * | 1975-09-08 | 1976-11-30 | Rockwell International Corporation | Transition apparatus |
JPS59119902A (en) * | 1982-12-25 | 1984-07-11 | Fujitsu Ltd | Electric power distributing and synthesizing circuit |
US5121090A (en) * | 1990-04-09 | 1992-06-09 | Tektronix, Inc. | Balun providing dual balanced outputs |
-
2004
- 2004-04-07 JP JP2007507285A patent/JP4445010B2/en not_active Expired - Fee Related
- 2004-04-07 EP EP20100181791 patent/EP2273605A3/en not_active Withdrawn
- 2004-04-07 WO PCT/US2004/010749 patent/WO2005109566A1/en active Application Filing
- 2004-04-07 EP EP04821964A patent/EP1735870A1/en not_active Withdrawn
-
2006
- 2006-11-06 NO NO20065111A patent/NO20065111L/en not_active Application Discontinuation
Patent Citations (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JPS6075101A (en) * | 1983-09-30 | 1985-04-27 | Sony Corp | Balun for microwave |
US4739519A (en) * | 1985-10-31 | 1988-04-19 | Narda Western Operations | Coplanar microwave balun, multiplexer and mixer assemblies |
US5379006A (en) * | 1993-06-11 | 1995-01-03 | The United States Of America As Represented By The Secretary Of The Army | Wideband (DC to GHz) balun |
Non-Patent Citations (2)
Title |
---|
JEONG PHILL KIM ET AL: "NOVEL CONFIGURATIONS OF PLANAR MULTILAYER MAGIC-T USING MICROSTRIP-SLOTLINE TRANSITIONS", IEEE TRANSACTIONS ON MICROWAVE THEORY AND TECHNIQUES, IEEE INC. NEW YORK, US, vol. 50, no. 7, July 2002 (2002-07-01), pages 1683 - 1688, XP001123758, ISSN: 0018-9480 * |
PATENT ABSTRACTS OF JAPAN vol. 009, no. 216 (E - 340) 3 September 1985 (1985-09-03) * |
Also Published As
Publication number | Publication date |
---|---|
EP2273605A3 (en) | 2011-03-23 |
JP4445010B2 (en) | 2010-04-07 |
JP2007533201A (en) | 2007-11-15 |
EP2273605A2 (en) | 2011-01-12 |
EP1735870A1 (en) | 2006-12-27 |
NO20065111L (en) | 2006-11-24 |
Similar Documents
Publication | Publication Date | Title |
---|---|---|
US6891446B2 (en) | Compact broadband balun | |
US6157329A (en) | Bandpass sigma-delta modulator employing high-Q resonator for narrowband noise suppression | |
Russell | Microwave power combining techniques | |
US5628057A (en) | Multi-port radio frequency signal transformation network | |
US6946880B2 (en) | Compact balun for rejecting common mode electromagnetic fields | |
WO2011047699A1 (en) | Test device and test method for measuring a phase noise of a test signal | |
US8829973B2 (en) | Switch mode circulator isolated RF mixer | |
JPH0452642B2 (en) | ||
Harrison | A broad-band frequency divider using microwave varactors | |
EP2273605A2 (en) | Compact balun for rejecting common mode electromagnetic fields | |
US3950703A (en) | Microcircuit reverse-phased hybrid ring mixer | |
US6498540B2 (en) | Broadband millimeter wave microstrip balun | |
US10483940B2 (en) | High-performance conversion between single-ended and differential/common-mode signals | |
KR100801837B1 (en) | Compact balun for rejecting common mode electromagnetic fields | |
US5945890A (en) | Ultra-wide bandwidth field stacking balun | |
US3932815A (en) | Broadband waveguide mixer | |
Yang et al. | A Millimeter-Wave Mixer-First Receiver with Non-Uniform Time-Approximation Filter Achieving $> 45\text {-dB} $ Blocker Rejection | |
US20050043002A1 (en) | Method and apparatus for direct digital to rf conversion using pulse shaping | |
KR100799590B1 (en) | Broad band active balun and balanced mixer using reactive feedback | |
JP2000236203A (en) | Broadband transmission line/balun | |
WO2007146535A2 (en) | High speed digital-to-analog converter | |
USRE29859E (en) | Broadband waveguide mixer | |
Kim et al. | A single balanced diode mixer with defected ground structure (DGS) lowpass filter (LPF) | |
Chiu et al. | A new parallel-strip power divider with enhanced isolation performance | |
Aslaksen | Integrated microwave power distribution network |
Legal Events
Date | Code | Title | Description |
---|---|---|---|
AK | Designated states |
Kind code of ref document: A1 Designated state(s): AE AG AL AM AT AU AZ BA BB BG BR BW BY BZ CA CH CN CO CR CU CZ DE DK DM DZ EC EE EG ES FI GB GD GE GH GM HR HU ID IL IN IS JP KE KG KP KR KZ LC LK LR LS LT LU LV MA MD MG MK MN MW MX MZ NA NI NO NZ OM PG PH PL PT RO RU SC SD SE SG SK SL SY TJ TM TN TR TT TZ UA UG US UZ VC VN YU ZA ZM ZW |
|
AL | Designated countries for regional patents |
Kind code of ref document: A1 Designated state(s): BW GH GM KE LS MW MZ SD SL SZ TZ UG ZM ZW AM AZ BY KG KZ MD RU TJ TM AT BE BG CH CY CZ DE DK EE ES FI FR GB GR HU IE IT LU MC NL PL PT RO SE SI SK TR BF BJ CF CG CI CM GA GN GQ GW ML MR NE SN TD TG |
|
121 | Ep: the epo has been informed by wipo that ep was designated in this application | ||
WWE | Wipo information: entry into national phase |
Ref document number: 2007507285 Country of ref document: JP |
|
WWE | Wipo information: entry into national phase |
Ref document number: 1020067020661 Country of ref document: KR |
|
NENP | Non-entry into the national phase |
Ref country code: DE |
|
WWW | Wipo information: withdrawn in national office |
Ref document number: DE |
|
WWE | Wipo information: entry into national phase |
Ref document number: 2004821964 Country of ref document: EP |
|
WWP | Wipo information: published in national office |
Ref document number: 2004821964 Country of ref document: EP |