1,721,517 research outputs found
Distributed amplifier based broadband and low spurious frequency doubler
No full textA circuit topology for a frequency doubler consisting of a distributed amplifier work-
ing under nonlinear regime is analyzed analytically and characterized experimentally. Fully-
distributed circuit topologies for the phase shifter used to realize the gate and drain artificial
transmission lines of the distributed amplifier are proposed. For these types of phase shifters,
it is shown that efficient rejection of the output odd harmonics is possible, but also low ripple
of the output power level on the output second harmonic is obtained. The proposed frequency
doubler has been designed for central input frequency equal to 5 GHz, and the designed cir-
cuit has been fabricated, too. The experimental conversion loss for the fabricated frequency
doubler is less than 4 dB and 7 dB, when the power level to the input is imposed to –1 dBm
and 5 dBm, respectively, while the input frequency is between 4 and 6 GHz
Broadband and small-size 3-DB ring coupler
Full text linkA topology for a 3-dB broadband and small-size ring coupler is proposed. It consists of fully distributed Composite Right-/Left-Handed phase shifters and a Lange coupler. For the fabricated coupler, the frequency bandwidth is one octave, centered on 1.5 GHz, while the footprint area is 25% compared to the conventional ring coupler topology. The experimental results are in good agreement with the expected ones, obtained by electromagnetic simulation
CRLH unit cells - The key for new design methods of distributed active and passive microwave devices and circuits
No full textRecent applications of CRLH unit cells
used to design distributed passive and active microwave
devices and circuits are presented. In particular, new
configurations for small-size passive devices based on
quarter-wavelength transmission line sections, as well as
microwave amplifiers, oscillators and frequency doublers
are analyzed. The performances of these new circuit
topologies are put into evidence numerically and the
results are validated by experiments
High power efficiency distributed oscillator based on composite-right-/left-handed unit cells
No full textA microwave oscillator topology based on CRLH (Composite Right-/Left-Handed) unit cells is
analyzed theoretically and experimentally tested. The oscillator consists of a CRLH based
distributed amplifier and a positive feedback realized by a simple transmission line. The oscillator
has two output ports, where the power levels are practically the same. For this topology, we have
found the oscillation condition and we demonstrate that each transistor gives the same contribution
to the power delivered at the two output ports, in this way, the output power is maximized. The
oscillator has been designed for a frequency of oscillation of 2.8 GHz and fabricated in hybrid
technology, by using InGaAs HEMTs and microstrip lines. The measured powers at the two output
ports are equal to 12.6 dBm and 10.4 dBm, the small difference between these values being given
by the insertion loss of the gate line. The experimental frequency of oscillation is 2.77 GHz, with a
difference of less than 1% in comparison with the expected value. Due to the frequency selectivity
of the CRLH unit cells, numerical simulations predict low phase noise for this configuration of
oscillator.
Broadband and small-size fully-distributed CRLH based ring coupler
No full textA topology for a 3-dB broadband and small-size ring
coupler is designed and numerically analyzed. It consists of
fully-distributed Composite Right-/Left-Handed phase shifters
and a Lange coupler. The frequency bandwidth is one octave
centered on 1.5GHz. The area occupied by the coupler is 25% of
the conventional ring coupler topology. The coupler has been
fabricated and it is ready for the experimental characterization
Design considerations and experimental results on composite right-/left-handed based distributed oscillator
No full textAn oscillator based on distributed amplifier realized by using CRLH (Composite Right-/Left-Handed) unit cells is designed and experimentally validated. The positive feedback consists of a transmission line which connects the input port and drain idle port of the amplifier. The remaining two ports of the distributed amplifier are the oscillator output ports. For this oscillator topology, the transistors give the same contribution to the output power. The measured powers at the two output ports are equal to 12.6 dBm and 10.4 dBm. The experimental frequency of oscillation is 2.77 GHz, the difference compared to the simulated value being less than 1%
Analysis and design of a new topology for a broadband and low spurious distributed frequency doubler
No full textA new distributed frequency multiplier
topology is proposed. The phase matching condition
accordingly to the order of frequency multiplication is
derived. Based on this topology, a frequency doubler for
8–12 GHz output frequencies is designed and analyzed
numerically. Due to the circuit topology, the fundamental
and third harmonics at the output may be suppressed
completely
Design considerations on balanced CRLH single-ended dual-fed distributed amplifier
No full textSingle-ended dual-fed distributed amplifier (SEDFDA) based balanced amplifier is analyzed and the layout is designed. The gate and drain artificial lines are realized with Composite Right-/Left-Handed (CRLH) phase shifters, having convenient topology for transistor connection. The amplifier design takes into account the catalog S-parameters of the transistors
Distributed oscillator based on Composite Right-/Left-Handed unit cells
No full textA circuit topology for a fixed frequency oscillator based on Composite-/Right-/Left-Handed distributed amplifier is proposed. For this topology, it is demonstrated that each transistor contributes equally to the output power. The oscillation condition is introduced, too. The oscillator has been designed and fabricated for a frequency of oscillation equal to 2.8GHz. The experimental and simulated results are in good agreement
Experimental results obtained on a new circuit topology of a broadband and low spurious frequency doubler
Full text linkA CRLH (Composite Right-/Left-Handed) based distributed frequency multiplier circuit topology is proposed. It is demonstrated that using fully-distributed CRLH based unit cells, low spurious output spectrum and flat output power level may be obtained for a large frequency bandwidth. To validate the proposed frequency multiplier, a frequency doubler is designed and fabricated. The experimental results have shown that the conversion losses on the output second harmonic is less than 9 dB and 7 dB, for input power level of -1 dBm and 5 dBm, respectively, within an input frequency bandwidth from 4 GHz to 6 GHz. In the same frequency bandwidth, due to the CRLH based circuit topology, the first and third output harmonics are well filtered
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